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0.M:» D.Sc., F.R.S., etc. 

Master of Trinity College, Cambridge 



First ^vfflished 1936 
Reprinted *936 



W HEN I rashly consented to write this book I did 
not reahse how difficult it would be and how 
long it would take. I have never kept a diary 
and my memory has always been very patchy, good for 
things which are amusing, bad for those which arc in- 
structive. I have, therefore, had to spend a good deal of 
time in verifying dates and I cannot hope to have escaped 
mistakes. Though some of the work has been trouble- 
some, much of it has been delightful. I have felt at times 

as if I were living my life over again, old friendships, 
which meant much to me seem to have sprung again into 
life and, as is the way with memory, one recollection 
kindles others until they stretch without a gap from long 
ago to yesterday. I have realised even more vividly than 
I did before how fortunate I have been throughout my 
life. I have had good parents, good teachers, good ctsl- 
leagucs, good pupils, good friends, great opportunities, 
good luck and good health. 

My father died soon after I went to the Owens College, 
and had it not been for the sacrifices made by my mother 
I could not have completed the course there or come 

to Cambridge. What I owe to my teachers, colleagues 
and pupils is told in this book. The events which really 
determined my career— going to Owens College and 
coining to Trinity with all that it has meant to me— were 
sheer accidents. I went to Owens because my father 
happened to meet a friend who had heard of Owens 



College — at that time very few had — and I came to 
Trinity because my teacher happened to be a Trinity 

I was lucky again in my opportunities. New dis- 
coveries were made which supphed new and more power- 
ful instruments for my researches just at the time I wanted 
them. Again, I have been blessed with remarkably good 
health. I began badly — ^for some months after I was bom 
I was not expected to Uve — ^but since then I have very 
seldom been iU. I cannot remember any day in the last 
sixty years when my work has been interrupted through 
bad health. 

Part of the account of the Cavendish Laboratory given 
in this book is taken jSrom a chapter I wrote in 1910 
for The History of the Cavendish Laboratory, a book which 
has been long out of print. The chapter, “ Physics in 
My Time'^ does not profess to give an account of all 
the discoveries made between 1870 and the beginning of 
the war, a period which is one of the most prolific in the 
history of Physics and would have required not a chapter 
but several volumes. I have confined myself to those 
which had special connection with my own work or that 
of my pupils, or of which I saw something while they 
were in progress. 

I wish to thank my wife and daughter for their valu- 
able assistance in reading the proofs, my daughter for 
preparing the Name Index, and my publishers for much 
valuable advice and for the care they have taken in the 
preparation of this volume. 


TiaNixY Lodge 
November 1936 




Chapter!. Boyhood and Owens College i 


Chapter II. Undergraduate Days: Cambridge Then 
AND Now 34 

Chapter III. Cambridge, 1879-1884 75 

Chapter lY. The Cavendish Laboratory— and Pro- 
fessorship OF Experimental Physics 99 

Chapter V. Psychical Research 147 

Chapter VI. First and Second Visits to America. 
1896, 1903 164 

Chapter VII. Visits to Canada and Berlin 194 

Chapter VIII. War Work— Cambridge during the 
War 20(5 

Chapter IX. Visit to America in 1923 243 

Chapter X. Some Trinity Men 267 

Chapter XL Discharge of Electricity through Gases ; 

The Discovery op the Electron ; Positive Rays 325 

Chapter XII. Physics in My Time 372 

Appendix 435 

Index of Names 439 

Index of Subjects 447 


List of Illustrations 

Sm J. J. Thomson 

From the painting by Fiddes Watt in the 
possession of the Royal Society 


Dr. Routh and Pupils for the Mathematical 
Tripos of January, 1880 

Facing page 

The Cavendish Laboratory 


Research Students, Cavendish Laboratory, 


Sir j. j. Thomson, 1902 

From the painting by Arthur Hacker in tlie 
Cavendish Laboratory 


Sir j. j. Thomson, circa 1922 


Trinity College, showing the Master’s Lodge 



Sir j. j. Thomson 


From the bust by F. Derwent Wood 

Plate I (Ch. xi) 


Plate n (Ch. xn) 




Boyhood and Owens College 

1 WAS born in Cheetham, a suburb of Manchester, on 
December i8, 1856 ; both time and place were fortunate, 
for the period between then and now has been one of 
the most eventful in the history of the world. From the 
beginning to the end, and especially in the latter half, there 
has been a quick succession of one stupendous event after 
another. Monarchies have fallen, and have been replaced 
by Republics and Dictatorships. Free trade, which as a 
Manchester man I naturally regarded for long as essential 
to the prosperity of the country, has gone too. But it is 
not of such things I shall speak in these reminiscences ; 
more in my province are the inventions and discoveries 
made in the period which have wrought great changes in 
our social life. When I was a boy there were no bicycles, 
no motor cars, no aeroplanes, no electric light, no tele- 
phones, no wireless, no gramophones, no electrical engin- 
eering, no X-ray photographs, no cinemas and no germs, 
at least none recognised by the doctors. 

It was a mere accident that I became a physicist ; it 
was intended that I should be an engineer. In those days 
the only way of entering this profession was to be appren- 
ticed to some firm of engineers, paying a considerable 
premium for the privilege. It was arranged that I should 
be^pprenticed to Sharp-Stewart & Co., who had a great 
reputation as makers of locomotives, but they told my 
father that they had a long waiting list, and it would be 

I B 


some time before I could begin work. My father happened 
to mention this to a friend, who said, “ If I were you, 
instead of leaving the boy at school I should send him while 
he is waiting to the Owens College : it must be a pretty 
good kind of place, for young John Hopkinson who has 
just come out Senior Wrangler at Cambridge was educated 
there ”, My father took this advice, and I went to the 

This accident, which I regard as the most critical event 
in my life and which determined my career, could not 
have happened in any Enghsh provincial town except 
Manchester, for there was no other which had anything 
corresponding to Owens College. And it could not happen 
now in any tovm in England, though now there are many 
which have such Colleges. I was only fourteen when I 
went to Owens College, and I believe that sixteen is now 
the minimum age at which students are admitted to such 
Colleges. Indeed the authorities at Owens College thought 
my admission such a scandal — I expect they feared that 
students would soon be coming in perambulators — that 
they passed regulations raising the minimum age for ad- 
mission, so that such a catastrophe should not happen 

The first thing I remember about my education was 
being sent when a very small boy to dancing classes. I 
remember them though it is more than seventy years ago, 
because I hated them so intensely ; after a short time, how- 
ever, the attempt to teach me dancing was given up as 
hopeless. After going for a year or two to a small school 
for young boys and girls, kept by two maiden ladies who 
were friends of my mother, I went to a private day school 
kept by two brothers named Townsend, at Alms HiU, 
Cheetham, which was near to where we hved. It wa*s a 



school which was not affected by the new views on educa- 
tion which were just then coming in. We were taught 
Latin from the Eton Latin Grammar, where the rules for 
syntax and grammar were in Latin, and we learnt these 
by heart before we knew what they meant. This was by 
no means so absurd as it might seem, as they were very 
skilfully written for their purpose. Erasmus is said to have 
had a hand in them. They rhymed, which made them 
very easy to remember ; and they were very sonorous, 
which made it quite a pleasure to roll them off. When I 
went to the Owens College, where they used a more up-to- 
date Grammar — think it was called the Public Schools 
Latin Primer — I thought it very pallid and arid, and much 
preferred the lusciousness of the other. When I removed 
my books to Trinity Lodge in 1918 I came across the copy 
I had used at school, which I had not opened for nearly fifty 
years, and found that when I once got started I could go 
on with the “ propria quae maribus ” and the as in presenti 
perfectum format in avi'\ without a slip. I think that now- 
adays not enough advantage is taken of the ease with which 
boys can learn things by heart, indeed some people seem to 
regard memory almost as something which ought to be 
apologised for. The way we were taught EngHsh was to 
make us learn by heart “ purple patches from Shake- 
speare, Byron, and Scott, and I think this a better way than 
just reading the notes at the end of school editions of the 
works of these authors, which is now not an unusual way of 
preparing for an examination. We did not write essays ; 
the only English “ composition ’’ we did was to write at 
the end of term a letter to our parents about what we had 
begti doing. This was dictated by the master of the form. 
I remember one of them which began, “ My dear Parents 
— England this day expects every man to do his duty 



was once the signal prelude to a great naval victory” — 
and thinking it would never have occurred to me to begin 
in that way. 

History was not much more than learning a large 
number of dates, geography a description of the boundaries, 
principal towns and rivers of various coimtries, with a 
little map-drawing. In mathematics we learnt the propo- 
sitions in the first book of Euclid by heart ; we did not 
do any algebra, but a great deal of arithmetic which was well 
taught. I think it forms the best introduction to mathe- 
matical ideas and is an excellent^inteHeetual gymnastic, 
for it is easy to set simple questions which cannot be solved 
by rule of thumb, but require thought. Our knowledge 
was prevented from getting rusty by an ingenious device : 
lessons stopped a quarter of an hour before school ended, 
then the master would ask the boy at the head of the form 
some question — ^it might be a date in history, a sum in 
mental arithmetic, the Latin for an English word or the 
Enghsh for a Latin one and so on ; if his answer was right 
he could leave at once ; if not, the question went on to the 
next boy, and so on until someone answered it correctly 
and went out. A new question was then put to the boy 
next to him, and this process was repeated. A boy could 
not get out before the end of school unless he answered 
a question correctly. We had to do preparation at home, 
which generally took about an hour and always included 
something which had to be written out, a piece of Latin 
translation, sums or a piece of poetry — great attention was 
paid to the handwriting in these, and we got very few marks 
if this was not satisfactory. There were no examinations, 
and the prizes were awarded on the work done during ^he 
year. On the whole, I think I did not learn less under this 
old-fashioned system than I should under a modern one, 



but then, as I have said, I left the school when I was very 

(As for games, the older boys played cricket and foot- 
ball and a number of minor games such as rounders, 
prisoners’ base, and a crude form of hockey called shinty 
which had no rule — or, if there was one, no one paid any 
attention to it — against raising the club, and I remember 
getting hit in the eye by a full swing. Fortunately it did 
not injure my sight. (Football then was rather a gruesome 
business ; “ hacking ” was allowed, that is, the forwards 
in the scrum just kicked at anything in front of them, 
whether it was the ball or the shins of the opponents ; 
the result was that after a game one’s shins were always 
bruised and often bleeding.^ We also played single-stick, 
an excellent game both as a gymnastic and as a training in 
keeping one’s temper under provocation, as a hit over the 
legs arouses emotions which it requires practice to suppress. 

Towards the end of my schooldays, the war between 
France and Germany broke out ; at first our sympathies 
were all with Germany ; we thought, like many people 
wiser than ourselves, that poor Germany would have no 
chance against the great army of France. It was not very 
long, however, before our sympathies were all the other 

When I was a boy I was, as I am now, very fond of 
gardening, and had a httle garden in which I was allowed 
to do as I liked. I spent the greater part of my pocket- 
money on a weekly gardening paper — there were no penny 
ones in those days. This paper was the ruin of my garden, 
for from time to time it gave such alluring accounts of 
sonje plant I had not got, that I felt I must buy a packet 
of seed and try to grow it. My garden was so small that 
the^only way I could find room for this was to pull up 


something already growing, so that most of my plants came 
to an untimely end. I was also, as I have been all my life, 
fond of searching for wild flowers and of reading books 
about them, and thought that when I grew up I should 
like to be a botanist. The scientific names of plants 
irritated me greatly ; it was the days when the Lmnaean 
system was almost universal, and I determined that if I 
became a botanist I would do all I could to purge botany 
from science. 

Natural l^story was pressed into the service of boys 
when I and sotne of my friends tried to raise money to buy 
wickets, bats and balls for a small cricket club we wanted 
to start, by having an exhibition of butterflies, moths, 
birds’ eggs and wild flowers which our relatives were 
expected to attend, and pay for admission. This worked 
quite well financially, but there was an unfortunate inci- 
dent. An aunt of mine, looking at an exhibit of a big 
moth with a pin stuck through it, saw that the moth was 
ahve and trying to get away. She was very indignant and 
rated the boy soundly for not killing it before pinning it 
down ; he excused tdmself by saying, “ Well if it’s not 
dead, it s its own fault. I’ve been pinching its head all 
morning.” \^other occasion, when I got some fun as ’ 
well as instruction from my excursions into science, was 
once when a friend came in as I was using a microscope my 
father had given me. I showed it to him, plucked a hair 
from my head and put it on the shde and told him to look 
at it ; he did and seemed very much interested, much more 
so than I had expected, for he was not very intelligent. 
He kept screwing it up and down. I thought perhaps the 
hair had been blown away. So I said, “ Can you see it ? ” 
Oh^yes,^ he said, I can see it.” ** Doesn’t it look very 
big ? ” “ It looks big enough, but I can’t see the number 


on it.” “ Number,” I said, “ what number ? ” “ Well,” 

he said, “ it says in the Bible that the hairs of our head are 
all numbered, but I can’t find any number on this.” 

Manchester has played a prominent part in the 
history of physical science, for in it, in the first half of 
the nineteenth century, Dalton made the experiments 
which led him to the discovery of the law of multiple 
proportion in chemical combination, and Joule those 
which were instrumental in establishing the principle 
of the Conservation of Energy. Notable discoveries, 
though not of the same rank as these, were made by 
Sturgeon, the inventor of the electromagnet, and the 
Henrys, father and son, who did good work in physical 

The Manchester Literary and Philosophical Society 
is, I believe, the oldest, as it is certainly quite one of the 
most important, of such societies. In 1781 it began, as 
such societies generally did, by informal meetings of a few 
friends in each other’s houses. ^ This developed into weekly 
meetings at a tavern ; then a house was built, and in 1800 
John Dalton, the great chemist, was appointed Secretary. 
He had come to Manchester shortly before this as teacher of 
mathematics in the newly established Manchester College, 
an unsectarian College, which was the germ from which 
Manchester New College developed. His laboratory was 
in the house of the Society, and his diary is still in their 
possession. It was pubhshed in Roscoe and Harden’s 

^ The only one of my connections who to my knowledge took any 
interest in scientific matters was G. V. Vernon, a cousin of my mother's, 
who was for some years one of the Honorary Secretaries of the Manchester 
Literary and Philosophical Society, He was a cotton spinner by trade — 
partner in the firm Vernon & Bazlcy, but a meteorologist by inclination, 
and published several papers on that subject, 



New View of the Origin of Daltons Atomic Theory, 1896. 
It shows that Dalton, influenced by the views of Newton, 
beheved in the existence of atoms long before 1803, when 
his great paper was read before the Philosophical Society, 
and also that, contrary to the view previously held, Dalton 
was not led to the discovery of the atomic theory by dis- 
covering the law of Chemical Combination in multiple 
proportion, but was led by the atomic theory to the dis- 
covery of this law. Though not the audior of the atomic 
theory, he has strong claims to have been the first to prove 
it, or at any rate to find evidence in its favour which, if 
not absolutely conclusive, was immensely stronger than 
any that had been obtained before. In 1817 he was 
elected President of the Society, and remained so until his 
death in 1844. He was not a fluent speaker, and when, 
as President, he had to make a few remarks when the 
reader of a paper stopped, he is reported to have sometimes 
contented himself by saying, “ This paper will no doubt 
be found interesting by those who take an interest in it 

Though he was one of the shyest and most retiring of 
men, the Manchester people knew that they had a great 
man Hving among them, and were proud of it. They 
showed their appreciation by raising in his lifetime a sum 
of ;^2000 for a statue by Chantrey. On the day of his 
funeral many of the mills and shops were closed ; and an 
important street in the city is called John Dalton Street. 

Dalton was succeeded as President by James Prescott 
Joule, who had been his pupil : he had refused, however, to 
let him go on to chemistry until he had read mathematics. 
Joule was only twenty-six when he became President, 
but four years before that he had discovered the very 
important law which bears his name, viz. that the heat 
produced in a given time in a circuit through which a 



current is passing is proportional to the product of the 
electrical resistance of the circuit and the square of the 
current. In 1843 he pubHshed the paper which contains 
the first measurement of the mechanical equivalent of 
heat, which, with his subsequent experiments on the same 
subject, were in the main responsible for the acceptance 
of the principle of the Conservation of Energy, This was 
a remarkable achievement for a young man only twenty- 
five years of age, and was a striking instance of how great 
generalisations may be reached by patient work. He 
began by supposing that heat was a substance and so could 
neither be created xior destroyed. He soon convinced 
himself that this could not be true ; he then measured 
the proportion between the heat produced when paddles 
were rotated in a vessel full of water, and the work 
required to rotate the paddle. He found that this did 
not depend on the kind of fluid in the vessel or the 
kind of machine used to churn it, and he came to 
the conclusion that whenever a certain amount of heat 
was produced a proportional amount of mechanical work 
must be spent. This did not meet with immediate ac- 
ceptance. Even William Thomson, who subsequently 
became one of his closest friends and greatest admirers, 
at first believed that it must be wrong. Thomson was 
profoimdly impressed by the power of the method intro- 
duced by Carnot in 1825, and called Carnot’s cycle, in 
predicting new physical phenomena ; for example, it 
follows from it that, since water expands on freezing, the 
melting point of ice must be lowered by pressure ; or 
again, since the surface tension of a soap film diminishes 
when its temperature rises, the temperature of a film must 
fall when it is stretched. Carnot’s cycle, in the form in 
which it was first published, involved the assumption that 



heat could neither be created nor destroyed. Thomson, 
however, showed later that this assumption was not 
essential ; and Clausius had, a short time before, come 
to the same conclusion. 

Joule, besides being an excellent experimenter, had a 
very clear mind and sound judgment. He was one of 
those physicists who have, I think, been more plentiful in 
this country than in any other, who, though not holding any 
Professorship or other official post, have devoted themselves 
to the advancement of science at their own cost and in 
their own laboratories. None of these have done work 
more important than Joule. When I was a boy I was intro- 
duced by my father to Joule, and when he had gone my 
father said, “ Some day you will be proud to be able to say 
you have met that gentleman ; and I am. 

A statue of him by Gilbert stands side by side with that 
of Dalton in the Town Hall of Manchester. 

John Owens, a Manchester merchant who died in 1846, 
left his estate to be devoted to the establishment of a 
College free from rehgious tests, for instruction in the 
branches of knowledge taught in the English universities. 
It was not, however, imtil 1851 tEat the College started ; 
the time was a bad one for realising any kind of property, 
and in addition there was a dispute as to what amount, if 
any, of religious instruction was consistent with the terms 
of the trust. Finally it was compromised by limiting the 
instruction to lectures on the Greek of the New Testament 
and the Hebrew of the Old. However, by March 1851 a 
Principal and a few Professors had been appointed and the 
College opened. The first year 62 students attended, 71 in 
the second, and then it began to decline, and fell to little 
more than half this number' by 1857. The Manchester 
Guardian j in a leader about this time, said, “ Explain it bow 


we may, the fact is that the College is a mortifying failure 
The Principal, Dr. A. J. Scott, resigned in 1857 ^^id the 
Professor of Classics, J. G. Greenwood, was appointed to 
succeed him, and remained Principal until 1889. 

Dr. Scott, who had suffered from bad health during his 
tenure of office, was in many ways a very remarkable man. 
He had been Professor of English Language and Literature 
in University College, London, before coming to Man- 
chester. Before that he had assisted Irving — the founder 
of the Catholic Apostolic Church — ^in his church in Regent 
Square, and a little later was deprived, for heresy, of his 
Hcence to preach in a Presbyterian church. He was the 
friend of Archdeacon Hare, Frederick Denison Maurice and 
George MacDonald. Not unnaturally his sympathies and 
interests were in the literary rather than the scientific ac- 
tivities of the College. The Manchester Grammar School 
satisfied to a very considerable extent the needs of literary 
students, and had the advantage of having a considerable 
number of closed scholarships at Brasenose College, Oxford, 
so that students who hoped to go to Oxford went to the 
School rather than to Owens College. 

Under Principal Greenwood the prosperity of the 
College began slowly to improve, and that improvement 
has gone on without interruption from then to now. In 
its development to a university its name has twice been 
changed, first to a College of the newly formed and 
now defunct Victoria University, and then to Manchester 

Owens College began in a house in Quay Street, 
Deansgate, which had once been the residence of Cobden, 
In his day Quay Street had been a fashionable residential 
quarter, but when I went to the College, in 1871, rather 
dilreputable slums reached on one side almost up to its 



doors. The house was not a large one, and as by that 
time the number of students had increased to about 500, 
we were very much cramped for space. The Engineering 
Department was housed in what had been the stables. 
The stable itself was converted into the Lecture Room, and 
the hayloft above it into the Drawing Office, which had 
to be reached by an outside uncovered wooden staircase. 
The Chemical Department was more fortunate, as an ad- 
jacent house was used for the Laboratory. The only thing 
that could be called a Physical Laboratory was a room in 
which the apparatus used for Lecture experiments was 
stored. The cramped space was not without its advan- 
tage. We were so closely packed that it was very easy for 
us to get to know each other. Arts and Science students 
jostled against each other continually ; a crowd of mathe- 
maticians would be waiting outside a lecture room for it to 
discharge a Latin or Greek class. Thus one of the chief 
defects of non-residential colleges, the lack of opportunities 
for social intercourse between the students, was almost 
absent. Though I was only two years in Quay Street and 
three in the comparatively palatial buildings in Oxford 
Road, to which the College moved in 1872, my most vivid 
recollections are those of the old Quay Street days ; in 
Oxford Road we had more room but less company, and 
fewer opportunities of making friends. 

Though Owens College was badly housed, no univer- 
sity in the country had a more brilliant staff of Professors. 
For Mathematics there was Thomas Barker, a Senior 
Wrangler and Fellow of Trinity College, Cambridge ; for 
Physics, Balfour Stewart ; for Engineeritag, Osborne Rey- 
nolds ; for Chemistry, H. E. Roscoe ; W. C. Williamson, 
the distinguished palaeo-botanist, took all Natural History 
for his province, and lectured on Botany, Zoology, ahd 


Geology. There was Stanley Jcvons for Logic and Politi- 
cal Economy. Adolphus Ward, who afterwards became 
Principal of Owens College, then Vice-Chancellor of Vic- 
toria University, then Master of Peterhouse and Vice- 
Chancellor of Cambridge University, was Professor of 
History and English Language ; and Bryce, who later 
became Lord Bryce and Ambassador at Washington, of 

Although he never published any papers on the subject, 
I have never knowm a better teacher of mathematics than 
Barker, and in some respects no one so good. His lectures 
were always very carefully prepared ; they were written 
out on the backs of old examination papers, and it was the 
belief of his pupils that he destroyed them as soon as they 
had been delivered, and prepared new ones each year. His 
object was to give us sound views on the fundamental 
principles of the various branches of mathematics rather 
than to train us in solving problems with great rapidity. 
It was not that we did no examples, for some were set at 
the end of each lecture, and in addition to the lectures 
there were two classes a week at which we did nothing but 
examples ; but the number of examples wc did was small 
compared with that usually done in schools. Some of the 
subjects on which he lectured were not, I believe, taught 
then at any other university : for example, we had lectures 
on what might be called the logic of mathematics. The 
first Professor of Mathematics at Owens College, Archi- 
bald Sandeman, was a pioneer in this subject and had 
written a book on it called Pelicotetics, The text of this 
was as difficult as its name ; there were pages without a 
stop of any kind, and though some of us began it I never 
kn^w anyone who got far. 



Another novelty in Barker’s teacliing was the intro- 
duction of Quaternions, a system of geometrical analysis 
introduced by Sir W. R. Hamilton. I should think I 
must be the only man living who learnt Quaternions 
before he had done any Analytical Geometry. Quater- 
nions attracted a good deal of attention in the early 
seventies, largely through the enthusiastic support of Pro- 
fessor Tait of Edinburgh, who wrote an elementary text- 
book on the subject. Though the ideas introduced by 
Hamilton were very interesting and attractive, and though 
many physical laws, notably those of electrodynamics, are 
most concisely expressed in Quatemionic Notation, I always 
formd that to solve a new problem in mathematical physics, 
unless it was of the simplest character, the older methods 
were more manageable and efficient. I do not suppose that 
the introduction of unusual subjects such as these in com- 
paratively elementary courses is always to be recommended, 
but I think it was successful in this case and that we worked 
all the better for it ; we regarded ourselves as pioneers and 
that it was up to us to make good. 

The thing nearest to Barker’s heart, however, was 
not mathematics but mosses, on which he was an 
authority. He lived a very simple life, was not married, 
and had been fortunate in his investments, so that he 
was able to retire in middle hfe to Derbyshire and 
devote himself to mosses. He left his estate to found 
a chair in Cryptogamic Botany in the University of Man- 
chester, into which Owens College had developed. 

I received great benefit from the teaching of Mr A. T. 
Bentley, also a member of Trinity College, who was 
lecturer in mathematics. He took the Lower Junior Class, 
in which I was put when I entered the College. I found 
his teaching very attractive and it was he who first aroused 



my interest in mathematics. Besides being a good teacher, 
he had a vigorous and breezy way with him which kept us 
alert and made his lectures very popular. 

i-As I was taking the engineering course, the Professor] 
I had most to do with in my first three years at Owens 
was Osborne Reynolds, the Professor of Engineering. He 
was one of the most original and independent of men, and 
never did anything or expressed himself like anybody else. 
The result was that it was very difficult to take notes at his 
lectures, so that we had to trust mainly to Rankine’s text- 
books. Occasionally in the higher classes he would forget 
all about having to lecture and, after waiting for ten 
minutes or so, we sent the janitor to tell him that the class 
was waiting. He would come rushing into the room 
pulling on his gown as he came through the door, take a 
volume of Rankine from the table, open it apparently at 
random, see some formula or other and say it was wrong. 
He then went up to the blackboard to prove this. He 
wrote on the board with his back to us, talking to himself, 
and every now and then rubbed it all out and said that was 
wrong. He would then start afresh on a new line, and so 
on. Generally, towards the end of the lecture, he would 
finish one which he did not rub out, and say that this proved 
that Rankine was right after all. This, though it did not 
increase our knowledge of facts, was interesting, for it 
showed the working of a very acute mind grappling with a 
new problem- ^ This was very characteristic of his research 
work. He wordd often begin with an idea which, after he 
had worked at it for some time, turned out to be wrong ; 
he would then start off on some other idea which had 
occurred to him while working at the previous one, and if 
this ‘turned out wrong he would start another, and so on 



until he found one which satisfied him, and this was pretty 
sure to be right. He often started off in the wrong direc- 
tion but he got to the goal in the end. He had a way of 
his own of doing most things. When he took up a prob- 
lem, he did not begin by making a bibliography and read- 
ing the hterature about the subject, but thought it out for 
himself from the beginning before reading what others 
had written about it. 

There is, I think, a good deal to be said for his 
method. Many people’s minds are more alert when 
they are thinking than when they are reading, and less 
liable to accept a plausible hypothesis which will not 
bear criticism. The novelty in his method of approach 
made his papers very hard reading — in fact I think it is 
probable that some of them have never been read through 
by anyone. He could, however, be clear enough when 
addressing a popular audience. Some of his Friday even- 
ing discourses given at the Royal Institution are models 
of clear exposition expressed in terse and nervous 
Enghsh. His best-known research is the one on the 
flow of water through cylindrical tubes. When the 
flow is slow the motion of the water is quite steady 
and there are no eddies, but this changes when the 
rate of flow exceeds a certain limit, the flow then becomes 

turbulent ”, and the stream is full of eddies. Reynolds 
investigated the conditions which determine this change, 
and the constant which determines the rate of flow at 
which it occurs is known as Reynolds’ constant. He made 
important discoveries m lubrication ; he was attracted by 
what may be called out-of-door physics, and wrote papers 
on the calming of waves by rain, on the singing of a kettle, 
and why sound travelling against the wind is not heard so 
well as when it travels with it. He made some very 



beautiful experiments on the behaviour of vortex rings in 
water. We owe to him the generally accepted theory of 
the Radiometer ; the most complete account of this is in 
his paper “ On certain Dimensional Properties of Matter 
in the Gaseous State ”, Phil. Trans., 1879, Part IL This 
paper is very difficult reading, so much so that a severe 
criticism of certain parts of it by Professor G. F. Fitz- 
gerald, Phil. Mag. [5] II, 1881, p. 103, was shown by 
Reynolds to be based on a wrong interpretation of his 
meaning. He worked out with great success the con- 
sequences which follow from the fact that collections of 
equal spheres can be piled ” in different ways ; that for 
example they may be arranged either as in Fig. A or Fig. B, 
and showed that a sack 
full of shot arranged 
as in Fig. B would be 
quite rigid, while if 
the shot were as in 
Fig, A it would be a b 

quite floppy. He called the subject dealing with effects of 
diis character “ dilatancy He was so impressed with the 
importance of it in connection with the structure of the 
universe that in his last publication, The Sub-mechanics of the 
Universe, he worked out a theory of the universe on the 
assumption that it was a collection of spheres in contact, and 
claimed that it was “ the one, and the only one conceivable, 
purely mechanical system capable of accounting for all the 
physical evidence as we know it This is the most 
obscure of his writings, as at this time his mind was begin- 
ning to fail ; it is the record, however, of a great amount 
of work by a man of great originality and it is probable 
that, as Sir Horace Lamb said in his obituary notice of 
Osborne Reynolds, ‘‘ a diligent study of it might bring to 

17 c 


light valuable results My personal relations with him 
when I was a student are a very pleasant recollection ; he 
was always very kind to me, had a winning way with him 
and a charming smile. 

My first introduction to physics was when I attended 
in my second year at Owens the lectures on Elementary- 
Physics given by Professor Balfour Stewart ; these I found 
very attractive and so clear that, young as I was, I had no 
difficulty in understanding them. He looked a very old 
man ; his hak was quite white, and I was very much sur- 
prised when I was told he was only forty-three. Quite 
at the beginning of his work at Owens he had been badly 
injured in a terrible railway accident, one of the worst on 
record, at Abergele, North Wales. After about a year he 
was able to resume work, and though he looked so much 
older his mind was as clear and vigorous as before. When 
a yoimg man, he had been assistant to Professor David 
Forbes at Edinburgh, and it was while at Edinburgh that 
he made his most important contribution to physics — the 
relation between the radiation and the absorption of radia- 
tion. In a paper published in the Edinburgh Transactions 
vol. xxu. p. I, March 1858, he enunciated the important 
principle that in any enclosure bounded by opaque walls, 
the radiation from any body of any kind of light must, 
when the temperature throughout the enclosure is uniform, 
be equal to the absorption of the same kind of light by 
the body. Thus, if the body gives out light of a particular 
wave-length it will absorb light of that wave-length, or if 
a body like a plate of tourmaline absorbs light polarised in 
one plane, it will, when radiating, give out light polarised 
in one plane. The same principle was published about 
a year and a half later by J^chhoff, to whom it is gener- 



ally attributed, as Stewart’s work attracted at first little 

Stewart was appointed as Director of the Kew Ob- 
servatory in 1859, and worked mainly at Terrestrial 
Magnetism and the Periodicity of Sun Spots. Some 
friction on account of this arose between him and the 
Committee of the Royal Society which controlled the 
work of the Observatory, who thought he did not pay 
enough attention to routine observations. In consequence 
of this he welcomed the opportunity afforded by a vacancy 
in the Professorship of Physics at Owens, to escape into 
more congenial surroundings. He had in 1866 published 
an exceptionally able textbook on heat, which contains 
a very clear account of the laws of radiation. 

In Quay Street the only approach to a Physical 
Laboratory was the room where the apparatus used for 
experiments was kept. When, however, the College re- 
moved in 1872 to the site which it still occupies imder a 
new name, this want was supplied. The new laboratory, 
though it would seem almost microscopic in comparison 
with modem laboratories, was, I believe, the largest out- 
side London at the time, and the first in which there were 
classes for practical work. These were not very largely 
attended, and the work of each student was not so rigidly 
prescribed as it has to be in the crowded classes of the present 
day. We were allowed considerable latitude in the choice 
of experiments. We set up the apparatus for ourselves 
and spent as much time as we pleased in investigating any 
point of interest that turned up in the course of our work. 
This was much more interesting and more educational than 
the highly organised systems which are necessary when 
the classes are large. Balfour Stewart was enthusiastic 

^ On this point see Lord Rayleigh, Collected Papers^ vol. iv. p. 494. 



about research, and. succeeded in imparting the same 
spirit to some of his pupils. I remember, shortly after 
I began to work in the laboratory, he was talking to me 
about sun spots, and said he had made a large number of 
observations which he thought might throw some hght 
on the connection between them and terrestrial pheno- 
mena, but that he had no time to reduce them. I ventured 
to say that if I could be of any help I should be glad to do 
what I could, and he gave me a number of observations to 
reduce. Though the work I did was purely arithmetical, 
I liked doing it and enjoyed the feeling that I was taking 
some part in real science. Some time after this, Stewart 
was trying to find out whether there is any change in 
weight when substances combine chemically. His method 
was to have some iodine at the bottom of a flask and to 
put in the flask a test-tube containing mercury ; the flask 
was then sealed up and its weight measured. The flask 
was then tilted, when the mercury ran out of the test-tube 
over the iodine and combined with it, and then the flask 
was weighed again. He asked me to make the weighings. 

I had made a good many without finding any difference 
or without there being an explosion of any kind. One 
Saturday afternoon, however, when I was alone in the 
laboratory, after tiltmg the flask, though the mercury ran 
over the iodine no combination took place. I held it up 
before my face to see what was the matter, when it 
suddenly exploded ; the hot compound of mercury and 
iodine went over my face and pieces of glass flew into 
my eyes. I managed to get out of the laboratory and 
found a porter, who summoned a doctor. For some 
days it was doubtful whether I should recover my sight. 
Mercifully I did so, and was able after a few weeks to get 
to work again. Modem physics teaches that a change of 


weight is produced by chemical combination, and enables 
us to predict what it should be. In the experiment I was 
trying, the change of weight would not be as great as one 
part in many thousand millions, so that it is not sur- 
prising that I did not detect it. 

Before I left Manchester I did a small piece of research 
which was published in the Proceedings of the Royal 

Stewart in his lectures paid special attention to the 
principle of the Conservation of Energy, and gave a 
course of lectures entirely on this subject, and naturally 
I puzzled my head a great deal about it, especially about 
the transformation of one kind of energy into another 
— akinetic energy into potential energy, for example. I 
found the idea of kinetic energy being transformed into 
something of quite a different nature very perplexing, and 
it seemed to me simpler to suppose that all energy was of 
the same kind, and that the “ transformation ” of energy 
could be more correctly described as the transference of 
kinetic energy from one home to another, the effects it 
produced depending on the nature of its home. This had 
been recognised in the case of the transformation of the 
kinetic energy of a moving body striking against a target 
into heat, the energy of the heated body being the kinetic 
energy of its molecules, and it seemed to me that the same 
thing might apply to other kinds of energy. One day I 
plucked up courage to bring this view before Stewart. 
I should not have been surprised if he had regarded me as 
a heretic of the worst kind, and upbraided me for having 
profited so Httle from his teaching. He was, however, 
quite sympathetic. He did not profess to agree with it, 
but thought it was not altogether irrational, and that it 
might be worth my while to develop it. 



Stewart had a strong turn for metaphysics, and, in 
conjunction with P. G. Tait, published in 1875 The 
Unseen Universe, which was an attempt to find a physical 
basis for immortality. This attracted a great deal of atten- 
tion, and a second edition was called for in a few weeks. 
The physical basis was “ Thought conceived to affect the 
matter of another universe simultaneously with this may 
explain a future State The authors attached so much 
importance to this that, to secure priority, they had taken 
the unusual step of pubhshing it as an anagram in Nature 
some months before the pubHcation of their book. The 
Unseen Universe was followed by Paradoxical Philosophy, 
but this was not nearly so successful. 

Towards the end of my stay at Owens, Arthur Schuster 
was also working in the laboratory and gave a course of 
lectures which I attended on Maxwell's Treatise on Electricity 
and Magnetism, which had just been published. 

It was at this time that J. H. Poynting returned to 
Manchester after taking his degree as third Wrangler at 
Cambridge, and the friendship, which lasted until his 
death in 1914 and which was one of the greatest joys of 
my hfe, began. He had exceptionally soimd judgment, 
a very original and acute mind, and a discussion with him 
always clarified my old ideas, often suggested new ones. 
In his paper on the transmission of energy in an electro- 
magnetic field he introduced entirely novel ideas about the 
path the energy takes. The vector which represents this 
path, one of the most important in elcctrodynamic theory, 
is called the Poynting vector. 

To his friends he was much more than a physicist, for 
he had a genius for friendship and a sympathy so delicate 
and acute that, whether you were well or ill, in high 


spirits or low, his company was a comfort and a delight. 
During a friendship of forty years I never saw him angry 
or impatient, and never heard him say an unkind thing 
about man, woman or child. 

No one did more for the development of Owens 
College than Professor H. E. Roscoe, who succeeded 
Frankland as Professor of Chemistry in 1857, and 
held the Professorship until his retirement in 1885, 
when he was elected Member of Parliament for the 
Southern Division of Manchester. When he became 
Professor, Owens College was poverty-stricken, badly 
housed, with very few students. When he left, it was a 
university with very considerable funds, fine buildings, 
and more students than any other similar mstitution out- 
side London. This was in the main due to Roscoe and 
Adolphus Ward, who was then the Professor of History, 
and subsequently Principal of the College. With the aid 
of Thomas Ashton, a rich cotton spinner who took a 
great interest in the College, they aroused the interest and 
obtained the assistance of many of the wealthy citizens of 
Manchester, who supplied sufficient funds to make these 
developments possible. 

Roscoe was pre-eminently a man of affairs, with a 
very attractive and affable personality, sound judgment, 
energetic, persuasive, and very fertile in devising schemes. 
As an example of this, when during the early years of his 
Professorship, the Civil War in America had, by stopping 
the supply of cotton, thrown thousands of workpeople out 
of employment through no fault of their own, he with 
two others organised for their benefit a series of evening 
entertainments of various kinds. Some of these were 
concerts, some lectures on science with many experiments. 



This scheme was a great success, the audiences averaging 
4000 a week during the four winter months in which they 
were given. Encouraged by the success of these lectures, 
he instituted in 1866 a series of penny lectures ; a penny 
was charged for admission, and each lecture was published 
and sold at that price. He began by giving all the lectures 
himself, but he was soon able to enHst the services of 
Huxley, Tyndall, Sir John Lubbock, Balfour Stewart and 
many others. At first the lectures were all given in 
Manchester, but later he lectured at other manufacturing 
towns in Lancashire and Yorkshire. He took with him 
his lecture assistant, Heywood, and the apparatus required 
for the lecture experiments was in a large case. The 
railway porters at the stations around Manchester believed 
that he was running a Punch and Judy show. After a 
time the scheme of lectures was put on a more permanent 
basis by the Gilchrist Trustees ; later still the universities 
took a part, and provided short courses of study in various 
subjects, literary as well as scientific, in many towns. 
Roscoe, however, had for the first eleven years undertaken 
all the arrangements connected with these lectures. 

They were the beginnings of a forty years’ campaign 
to make the public realise die importance of science, to 
get more science taught in schools, to make science play 
a larger part in our industries, and to persuade the Govern- 
ment to make grants to universities and colleges for 
teaching and research. He was tireless in his efforts ; 
he wrote articles, he made speeches, he served on many 
Royal Commissions and took a very active part in the 
preparation of their reports, which attracted great atten- 
tion and produced a very marked effect on public opinion. 

He was elected M.P. for South Manchester in 1885. 
His selection as the candidate was very striking evidence 



of his popularity. The party managers had selected an- 
other candidate whom Roscoe was to propose, but at the 
pubhc meeting to choose a candidate someone at the be- 
ginning of the proceedings suggested his name. This was 
received with great enthusiasm and carried unanimously. 
He was much the most effective representative science 
has ever had. His opinion carried great weight in the 
House ; he had no axe to grind, he was not a manu- 
facturer and he had given up his Professorship on entering 
Parliament, but he had the confidence both of manu- 
facturers and of teachers. He was popular and worked 
hard, with the result that the scientific aspects of the BUls 
before Parliament received adequate consideration. He 
lost his seat at the election in 1895, when he was beaten 
by 76 votes by the Marquis of Lome, and did not make 
any attempt to enter ParUament again. He had done a 
great work : it is hardly an exaggeration to say that the 
recognition of the importance of science for the welfare 
of the nation hardly existed when he began it ; teaching 
of science in schools was described in a report of a Royal 
Commission as being “ regarded with jealousy by the staff, 
with contempt by the boys, and with indifference by the 
parents Now some science is taught in all schools and 
a good deal in a great many. Most of them have physical 
and chemical laboratories, which are in many cases large, 
well designed and well equipped with apparatus. There 
were then none of the Schools of Technology which are 
now to be found in most manufacturing towns ; some of 
these are magnificent buildings, erected by the municipal- 
ities at great cost, and provided with the most expensive 
apparatus. There were no Government institutions like 
the National Physical Laboratory for research, both in pure 
physics and for solving difficulties which manufacturers 



meet with in the course of their business. There were no 
laboratories for research in problems of importance to 
the army, navy or air force, such as are now to be found 
at Woolwich, Teddington and Famborough, nor any of 
those started and subsidised by the Board of Scientific 
and Industrial Research, like the Fuel Board, the Food 
Board, and Research Laboratories in most of the industries 
of the country. 

There were no scholarships for enabling students to 
take a course of research after taking a degree at a univer- 
sity. Then no one, except he held a teaching post or had 
private means, could undertake research, as there was no 
money to be made by it. It is very different now, when 
research is a recognised profession and a fairly lucrative one. 

Besides the laboratories subsidised and originated by 
Government departments, many great firms, acting on the 
principle Heaven helps those who help themselves, have 
instituted research departments of their own, with large 
laboratories with men of great scientific ability at their 
head, and with a large staff of workers who have been 
trained at the universities in research. Imperial Chemical 
Industries and the General Electric Company are con- 
spicuous examples of this. Another instance, in which a 
pupil of mine took part, is that of Messrs Tootal, Broad- 
hurst Lee Co., Manchester ; they are makers of cotton 
goods and they realised how gready the use of these would 
be extended if, like woollen goods, they did not crease. 

If you squeeze a cotton handkerchief up in your hand, 
the creases remain after your hand is taken away, while if 
you squeeze awooUen cloth the creases will come out auto- 
matically. In consequence of the creasing, cotton dresses 
soon look untidy and so are out of favour. Tootal 
Broadhurst started a research department to tackle this 


problem, and put an old pupil of mine, Mr R. S. Willows, 
in charge. The problem took many years to solve and the 
investigation cost a good deal of money, but at last it was 
done and uncreasable cotton fabrics were obtained. The 
result is that, in spite of the depression in the cotton trade 
which has caused heavy falls in the price of most cotton 
shares, theirs are higher than they were before the depres- 
sion. This is a very definite and direct demonstration of 
the advantages which a business may derive by having a 
research department as part of its organisation. 

Changes such as I have mentioned did not come of 
themselves nor were they the work of one man. Huxley, 
Norman Lockyer, Lubbock, Michael Foster, Rucker and 
many others took an active part in the campaign, but no 
one was more successful or more active than Roscoe. 
Perhaps the most important factor of all was the interest 
aroused in science by great and revolutionary discoveries 
such as electric waves, argon, Rontgen rays and radium, 
which began in the early eighties and has continued ever 
since. This produced a crop of very substantial benefac- 
tions for the advancement of science, and also made it much 
easier than it would otherwise have been to persuade the 
Government to make large grants for the same purpose. 

Roscoe’s work as a chemist was in teaching and organisa- 
tion rather than in discovery ; liis original work was done 
quite early in his career, some of it in Bunsen’s laboratory 
before he came to Owens College. He had the greatest 
veneration and love for Bunsen, and looked at chemistry 
from the same point of view. Bunsen was fond of saying 
that one new chemical fact, even an unimportant one, 
accurately determined, was worth a whole congress of 
discussion of matters of theory ; and this was Roscoe’s 
opinion too. 



Itwas amusing to hear Roscoe’s treatment in his lectures 
of the idea of atoms ; when he was dealing with the law 
of chemical combination in multiple proportions he could 
not altogether evade it, but he obviously regarded it as 
somewhat flighty and Bohemian, and though it was evi- 
dently related to this very respectable and indispensable 
law, it was just as well not to parade the relationship. It 
was the irony of fate for Roscoe twenty years afterwards 
to discover, in the rooms of the Manchester Literary and 
Philosophical Society, Dalton’s diary, which showed that, 
contrary to the view which he and others had held, it was 
the atomic theory that led to the law of chemical combina- 
tion, and not that law to the atomic theory. Roscoe 
forgot that though a theory might be Bohemian it might 
be the parent of very respectable facts. 

tfiis courses of lectures were carefully arranged, were 
clear, and illustrated by plenty of experiments, which almost 
invariably came off. Once, when one did not, he rose to 
the occasion. He had told the class that when tlie contents 
of one test-tube were poured into tliose of another, the 
latter would turn blue. His assistant, Heywood, tried the 
experiment but something had gone amiss and the tube 
turned a bright red. He said, Hold the tube up, Hey- 
wood, so that the class may see it. You see, gentlemen, 
what a beautiful and very pecuHar blue it is.”.) If you 
remembered his lectures you woiJd have a very useful 
knowledge of the properties of the chemical elements. I 
did not for my own part &d them very inspiring, though 
no doubt those who were already interested in chemistry 
found them very interesting. His Lessons in Elementary 
Chemistry contained a surprisingly large amount of informa- 
tion in a comparatively small space. It had an enormous 
circulation, over 200,000 copies having been sold by 1906. 



I suppose for nearly forty years practically every English- 
speaking student of chemistry began by reading the 

By the time he left Owens its Chemical Department 
had become the best organised and the best equipped 
in the country, attended by over a hundred students. It 
was the first in England to have a Professor of Organic 
Chemistry, Schorlemmer, who was appointed in 1874 after 
having been a demonstrator for thirteen years. The 
department was a pioneer in yet another respect, for the 
Dalton Chemical Scholarship, estabhshed in 1856 in 
memory of Dalton, was to be awarded to the student in 
the chemical laboratory who did the best piece of original 
research. This was the first scholarship in England awarded 
for original research. 

Besides his academic work, Roscoe did much by his 
own personal efforts to promote the application of science 
to industry. The manufacturers in Lancashire believed in 
him and were constantly coming to consult him as to the 
way diey should get over difficulties which had cropped 
up in their works. He had a private laboratory at the 
College in which he made experiments to solve such prob- 
lems. (He was a very genial and hospitable man and im- 
mensely popular with his students, and often asked them 
to his house, I remember on one occasion when I wa5 
there, von Helmholtz, the great German physicist, and his 
daughter were staying in the house. It was the custom in 
those days for the hostess after dinner to ask some ladies 
who had been at the dinner to sing. Mrs Roscoe asked 
Miss Helmholtz, who said she would sing a certain song if 
someone would play the accompaniment. No one offered 
to do so, so she beckoned to her father and he came and sat 
down to the piano ; she hummed the tune, and he for a 



few minutes kept beating it out with one finger, then he 
said he thought he could play it. He did so, and she sang 
her song. 

When I went to the Owens College, I intended to 
take three years over die Engineering Course. Actually I 
remained at the College for five years. At the end of my 
second year my father died, when he was only thirty-nine, 
and the idea of my becoming an engineer had to be given 
up, as my mother could not afford the very large premium 
required for me to become an apprentice, which was the only 
avenue to the profession in those days. I had won some 
small scholarships which helped to pay the fees, and it was 
determined that I had better finish the three years' course, 
and obtain the certificate of engineering granted to those 
who had passed through the course to the satisfaction of 
the authorities. This I did, and got, besides the certificate, a 
scholarship in engineering and a prize for an essay on some 
engineering subject. This was the end of my career as an 
engineer, for Professor Barker advised me to stay at the 
College for another year and go on with mathematics and 
physics, and then try for an entrance scholarship at Trinity 
College, Cambridge. This was another turning-point in 
my career, for I had never thought of the possibility of going 
to Cambridge. The proposal was very attractive to me, 
for throughout tlie engineering course the subjects which 
interested me most, and in which I had done best, were 
mathematics and physics. I stayed on at the College, taking 
the higher classes in mathematics and physics and working 
at the physical laboratory. I tried in the spring of 1875 for 
an entrance scholarship at Trinity College, Cambridge : 
except for the examinations at the end of each course of 
lectures, this was the first time I had been in for an examina- 


tion. My parents disliked examinations for young boys, and 
so, unlike the majority of my contemporaries at Owens, 
I had not taken any of the examinations of the London 
University which led to a degree. I was quite unsuccess- 
ful at my first attempt to get a scholarship at Trinity, and 
did not even qualify for an exhibition. The examiner 
wrote to Professor Barker and said that I should have done 
better if, instead of reading the higher subjects in mathe- 
matics which were not included in the examination, I had 
concentrated on getting a thorough grounding ’’ in the 
lower ones. This I think was true, but I am very glad that 
I had not done so. A “ thorough training in elementary 
subjects ” is often interpreted as reading the subjects in- 
cluded in the entrance scholarship examinations over and 
over again, and doing a great number of trivial examples 
in them. I had no idea of the extent to which this might 
be carried until I was chairman of a Royal Commission on 
Education, when evidence was brought before us that in 
some cases the boys, who were to be sent in to compete 
for entrance scholarships, did little in the two years before 
the examination but write out answers to papers set m 
previous examinations. Under this system the boys get 
more and more fed-up with mathematics the longer they 
are at it, while if they from time to time took up a new 
subject instead of revising an old one their interest in mathe- 
matics would continually increase, and they would come up 
to the xiniversity fresh and eager instead of stale and bored. 
I tried again the next year for an entrance scholarship and 
was successful, as I got a minor scholarship of ^^75 a year 
together with a subsizarship which entitled me to certain 
allowances. I think few can have owed more to scholar- 
ships than I do, for without them I could not have stayed 
at Owens or gone to Trinity. I must also express my 



gratitude for a scholarship I received from the Grocers* 
Company after I had been some time at Trinity ; it was of 
great service to me. Many years later they made me an 
Honorary Member of their Company — an honour which I 
value very highly. 

Several of my contemporaries at Owens attained dis- 
tinction in after-hfe. One of them, who was also my con- 
temporary at Cambridge, became Archbishop of Perth in 
Western AustraUa. Six of them became Professors at 
either Oxford or Cambridge, one of them became Whip 
for the Liberal party, another President of the Institution 
of Civil Engineers. Perhaps the most widely known was 
G. R. Gissing, the noveUst ; his novels are largely auto- 
biographies, and the experience of the characters in his 
books when at College are his own experiences at Owens. 
For example, in Born in Exile, Whiteway College is 
Owens and one of its Professors is Adolphus Ward, 
who was Professor of English Literature and History 
in Gissing’s time. Ward at once recognised Gissing*s 
ability. I can remember at one of the annual meetings 
which were held at the end of each session. Ward, 
when announcing that Gissing had gained the prize 
for the Enghsh poem, said he had written a very rare 
thing, a prize poem that was real poetry. Ward took 
a great interest in Gissing, and was a good friend to him 
when he badly needed one. I did not know Gissing in- 
timately, as we were not in the same year and did not meet 
at lectxires, which were the usual places for meeting one’s 
friends. As I remember him, he was pale, thin, listless, and 
looked and lived as if his means were small. After he left 
the College he lived by literature, but for many years he 
had a terrible struggle, hardly earning enough to keep 
body and soul together, and thinking when he could ajfford 


Undergraduate Days: Cambridge Then and Now 

I CAME up to Trinity College in October 1876 and have 
‘‘ kept ” every term since then, and been in residence 
for some part of each Long Vacation. As there was at 
the time no room in College when I came up, I went into 
lodgings at 16 Malcolm Street, intending to come into 
College when rooms were available. I found, however, 
the lodgings so comfortable and my landlady — Mrs Kemp, 
the widow of a Manciple at Trinity— so attentive, that I 
stayed in them for four years and did not come into College 
until I became a Fellow. I have never been able to remem- 
ber, while I was working, to attend to a fire, nor work to 
any advantage when the room got cold, so I got on much 
better in lodgings where there was always someone about 
to look after the fire, than in rooms in College where the 
bedmaker would be away for the greater part of the day. 
L My tutor was Mr J, M. Image : he was a classic, and I 
found this an advantage, for he let me choose the mathe- 
matical lectures I attended, whereas if he had been a 
mathematician he would have made me go to his own 
lectures. He was very helpful in other matters in which 
I required his assistance. The Master was Dr. W. H. 
Thompson, about whom I shall have something to say 
later, and the four tutors were Joseph Prior, H. M. 
Taylor, Coutts Trotter and Image. They were linked 
together in the song : 



If little Joe Prior 
Would only grow higher, 

Not Trotter, nor Taylor, nor Image Esquire 
Would be half such a man as little Joe Prior. 

The point of “ Image Esquire” was that Image, when he 
met the freshmen at the beginning of the term in his class- 
room, informed them that he would not open letters 

addressed Image, Esq. ; we must write — and here 

he wrote on the blackboard— J. M. Image, Esq. 

At that time it was not possible to take the Little-Go 
before the end of the first term, and Greek was compul- 
sory. I had not done any Greek, so I went to my tutor^s 
lectures on the Greek for the Little-Go. By the aid of 
these, Bohn’s translation of the set book, and a Greek 
Grammar specially written for the Little-Go, and which 
contained a long Hst of words which were irregular to 
the point of impropriety in their behaviour, not one half 
of which my classical friends had ever come across, I got 
through. I did not spend much time over Greek, not 
more than two hours a day for less than two months, 
but the time so spent was utterly wasted : it was not 
the slightest training in literature nor anything but a 
useless strain on one’s memory. 

Besides attending lectures on Greek I also, like the great 
majority of those aspiring to obtain a good place in the 
Mathematical Tripos, “ coached ” with Routh, the most 
famous of mathematical teachers. Routh’s teaching was 
not in the least like what is ordinarily understood by 
** coaching ”, it was in reality a series of exceedingly clear 
and admirably arranged lectures, given to an audience 
larger than that attending the lectures of many of the mathe- 
matical Professors or College Lecturers. I had heard so 


much of Routh’s teaching that I went to his class with great 
expectations. I confess at first I was somewhat disap- 
pointed : his lecture was quite clear, but there was nothing 
particularly novel or striking about what he said, and, 
taking any particular lecture, I had heard as good a one 
from other teachers. After a short time, however, I 
began to appreciate their merits, but to do this one must 
take into account what these lectures had to do. The 
mathematical tripos at the time I read with him included 
practically all the branches of pure and applied mathematics 
known at that time, and the examination was competitive 
— leaving out a subject would involve the risk of losing 
marks. The marks assigned to any subject might be a 
small fraction of the whole, so that several subjects might 
be omitted without altering the class in which the candidate 
was placed ; but it would alter materially his position in 
the class, and for men who hoped to be near the top of the 
tripos this was aU-important. The best candidates read 
by far the greater part of the subjects, and they had to do 
this in three years and a term. A course of instruction 
which would give an adequate knowledge of such a large 
number of subjects in so short a time required a time-table 
that had been most carefully thought out and thoroughly 
tested, and everyone knew that he would get this if he 
went to Routh. He took his pupils in classes, and there 
were usually about ten in a class, and two such classes for 
each year. You were placed in one class or another at the 
beginning, according to the amount you had read and how 
you had done in die entrance scholarship examination 
before coming up, and the great majority of his pupils 
had taken this examination. Most of us remained through- 
out our reading with him in the class he had put us in at 
first. In his lectures he took us through the best textbook 


on the subject, the parts which the author had treated satis- 
factorily he just told us to read : when the book was 
obscure he made it plain ; when the proof of a theorem 
was longer than need be he gave us the shortest one ; when 
the author had put in something that was not important 
he told us not to read it ; when he had omitted something 
that was important he supplied the omissions. These 
diversions made the lectures more interesting and more 
easily remembered. His lectures on Rigid Dynamics, on 
which he had written the standard textbook which had 
been translated into several languages and which is still 
the standard work on the subject, were not so interesting 
as those on other subjects. He naturally had not so many 
opportunities for criticism. 

The lectures were supplemented by manuscripts in his 
own handwriting on parts of the subjects which had not 
yet got into the textbooks and on which questions might 
possibly, though not probably, be set in the tripos. He 
did not touch on these in his lectures but referred us to the 
manuscripts, which were placed in a room next to his 
lecture-room at Peterhouse and which was open to all his 
pupils. Some copied them out, but as they were generally 
of considerable length and took a long time to copy, I 
contented myself with reading them. Another important 
part of his system of teaching was the weekly problem 
paper, which contained about a dozen problems taken from 
the different subjects set in the tripos ; one week we could 
take as much time as we pleased in solving the problems, 
the next we were expected to do them in three hours, the 
time allowed for such a paper in the tripos. We sent the 
papers in at the end of the week, and on the next Monday 
morning a complete solution of the paper in Routh’s hand- 
writing was placed in the pupils’ room, together with a 



list of the marks each pupil had obtained. This introduced 
a sporting element, and made us take more trouble over 
them than we should otherwise have done. 

Routh’s system certainly succeeded in the object for 
which it was designed, that of training men to take high 
places in the tripos ; for in the thirty-three years from 
1855 to 1888 in which it was in force, he had 27 Senior 
Wranglers and he taught 24 in 24 consecutive years. 
Results like these could not have been obtained unless he 
had been a bom teacher, as he was, and had spent, as he had, 
time and labour in keeping his technique up to the mark. 
His lectures were given in a conversational way ; he was 
never eloquent, never humorous, but always clear. I do 
not think he would create enthusiasm for mathematics in 
those who had not it already, but he could better than any- 
one else give to students during their stay at Cambridge 
a sound and substantial knowledge in all the important 
branches of mathematics pure and applied. Until quite 
near the time when he gave up “ coaching ”, candidates 
for the Mathematical Tripos were expected to be acquainted 
with the whole of the wide range of pure and applied 
mathematics included in the examination. The range of 
reading was much wider and there was much less specialisa- 
tion under this system than in the ones which since 1882 
have succeeded it, where the tripos is divided into two or 
more parts. The more elementary subjects are grouped 
in one part, and candidates are allowed to select a small 
number of the more advanced subjects for the other 

There is naturally, when we look back on our early days, 
a kind of glamour over many of our experiences and they 
look more attractive than they did at the time or than they 
would to an unbiassed judgment, but examinations are 



about the last things to which sentiment would cling, and 
I do not think it is prejudice which makes me prefer the 
system in vogue when I took my degree to those which 
succeeded it. I am glad that I came under the older system, 
for I probably read much more pure mathematics than I 
should have done if I had taken my degree a few years 
later. I have found this of great value {cest le premier pas 
qui coute), and it is a much less formidable task for the 
physicist, who finds that his researches require a knowledge 
of the highest parts of some branch of pure mathematics, 
to get this if he has already broken the ice, than if he has 
to start ah initio, Routh was such an interesting figure in 
the history of mathematics that I hope to be pardoned if I 
say a few more words about him. Example is better than 
precept, so he who teaches would-be Senior Wranglers 
ought to have been one himself. Routh fulfilled this con- 
dition, for he was Senior Wrangler in the year when Clerk 
Maxwell was second. Perhaps no other man has ever 
exerted so much influence on the teaching of mathematics ; 
for about half a century the vast m^'ority of professors 
of mathematics in English, Scotch, Welsh and Colonial 
universities, and also the teachers of mathematics in the 
larger schools, had been pupils of his, and to a very large 
extent adopted his methods. In the textbooks of the time 
old pupils of Routh’s would be continually meeting with 
passages which they recognised as echoes of what they had 
heard in his classroom or seen in his manuscripts. 

He was the son of Sir Randolph Routh, K.C.B., and 
was born at Quebec. He came to England and studied 
mathematics under De Morgan at University College, 
London ; he entered at Peterhouse, Cambridge, in 1850. 
Clerk Maxwell also came up to that College in this year, 
but after one term migrated to Trinity. Routh, like 



Maxwell, studied mathematics under Hopkins, the great 
“ coach ” at that time, who had taught Stokes and William 
Thomson, and scored 17 Senior Wranglers before he re- 
tired. Routh was Senior Wrangler and bracketed with 
Clerk Maxwell for the Smith Prize. He began taking 
pupils soon after taking his degree, and it was not long 
before practically all the best men came to him for tuition. 
He found time, in spite of all his private teaching, to write a 
good many papers containing original researches in mathe- 
matics. These were aU of high quahty ; his most im- 
portant work was, however, in the essay, “ A Treatise on 
the Stability of Motion, particularly Steady Motion ”, with 
which he won the Adams Prize in 1877. In this he intro- 
duced what he called “ a modified Lagrangean Function ” 
which increased greatly the scope and power of Lagrange’s 
method, the most general and powerful of all dynamical 
methods. Routh’s work has been of fundamental import- 
ance in the appHcation of dynamics to problems in physics. 
He anticipated Sir WHliam Thomson and von Helmholtz, 
who had independently discovered the same theorem. He 
was elected a Fellow of the Royal Society for his contribu- 
tion to mathematics. 

The regularity of Routh’s life was almost incredible ; 
his occupation during term time could be expressed as a 
mathematical function of the time which had only one 
solution. I believe one who had attended his lectures could 
have told what he had been lecturing upon at a particu- 
lar hour, and on a particular day, over a period of twenty- 
five years. The fact that year after year he gave the same 
lectures at the same time did not make him stale as it would 
most people. He might, as far as one could judge from 
his manner, have been deHvering each lecture for the fir t 



His way of taking exercise was as regular as his lec- 
tures : every fine afternoon he started at the same time for 
a walk along the Trumpington Road ; went the same dis- 
tance out, turned and came back. His regularity was not, 
as might perhaps have been expected, accompanied by 
formal and stereotyped manners ; these were very simple 
and kindly and we were all very fond of him. This was 
shown very markedly when in 1888 he gave up private 
tuition. His old pupils presented to Mrs Routh his portrait 
by Herkomer, and took the opportunity of expressing 
either by letter or by their presence at the meeting in Peter- 
house, where the presentation was made by the late Lord 
Rayleigh, their gratitude to him for his teaching. I share 
to the full this feeling. It was a long-established custom 
for Routh’s pupils to be photographed in a group in the 
term before the examination for the tripos. A collection 
of these would show what the great majority of the mathe- 
maticians of the last fifty years, and many other people 
who obtained eminence in other walks of life, looked like 
when they were undergraduates. My class at Routh’s 
contained Joseph Larmor, Senior Wrangler and First 
Smith’s Prizeman, who subsequently, like Newton and 
Stokes, became Lucasian Professor and representative of 
Cambridge University in Parliament, and was also, like 
Stokes, Secretary of the Royal Society ; W. B. AUcock, who 
was Third Wrangler and became a Fellow of Emmanuel, and 
a most efficient and devoted teacher of mathematics in the 
College ; andHomersham Cox, who was Fourth Wrangler 
and later a Fellow of Trinity College. Cox was one of the 
clearest-headed men I ever met but remarkably absent- 
minded. He became for a time a medical student : he 
did not take this very seriously. On one occasion, when 
in for one of the parts of the M.B. Examination, he found 


himself confronted with a paper on a subject which he had 
forgotten was included in the examination. He went to 
India as Professor of Mathematics in the University of 
Allahabad and was very successful in gaining the affections 
of his Indian students ; he had a very genuine sympathy 
with many of their opinions. Another member of 
Routh’s class was E. J. C. Morton of St. John’s College, 
who was President of the Union, an “ Apostle ”, and sub- 
sequently Member of Parhament. Martin Conway of 
Trinity, now Lord Conway, who has won great distinc- 
tion in art, in poHtics and mountaineering, was a member 
for one year and then deserted mathematics for art. 
Very striking evidence of the importance attached to 
Routh’s teaching is that so many undergraduates, many of 
them, like myself, poor men, were willing to pay his fees, 
amounting to a year, to get it. This made mathe- 
matics a more expensive subject than classics or history, 
where private tuition was not nearly so general, and 
students were content with the lectures given by the 
Professors and College Lecturers. Though no doubt 
most of us went to Routh because we thought that we 
should get a higher place in the tripos by doing so, the 
teaching itself was well worth the extra expense. 

Besides going to Routh, I went to lectures in Trinity 
College given by W. D. Niven on mathematical physics, 
mainly on Maxwell’s treatise on Electricity and Magnetism 
which had then lately been pubhshed, and also lectures by 
J. W. L. Glaisher on pure mathematics. From both these 
I derived great benefit. Niven was not a fluent lecturer 
nor was his meaning always clear, but he was profoundly 
convinced of the importance of Maxwell’s views and 
enthusiastic about them ; he managed to impart his 
enthusiasm to the class, and if we could not quite under- 


stand what he said about certain points, we were sure 
that these were important and that we must in some way 
or other get to understand tliem. This set us thinking 
about them and reading and re-reading Maxwell’s book, 
which itself was not always clear. This was an excellent 
education and we got a much better grip of the subject, 
and greater interest in it, than we should have got if the 
question had seemed so clear to us in the lecture that we 
need not think further about it. The best teacher is not 
always the clearest lecturer but the one who is most 
successful in making his pupils think for themselves, and 
this Niven by his enthusiasm certainly did. After Max- 
well’s death Niven published for the University Press his 
collected papers, and prefaced them by an admirable 
biographical notice, 

Niven was one of the best and kindest friends I 
ever had ; he was very kind to me from the time I 
came up as a freshman. He often asked me to go 
walks with him. I went very often to his rooms and, 
through him, I got to know many of the Fellows of the 

He was an Aberdonian. He was bracketed with 
James Stuart as Third Wrangler in 1866 ; his brother 
Charles was Senior Wrangler in 1867 and afterwards 
Fellow of Trinity, and Professor of Natural Philosophy 
at Aberdeen and Fellow of the Royal Society ; and his 
brother James was bracketed Eighth Wrangler in 1874, 
afterwards Fellow of Queens’ and Medical Officer of 
Health for Manchester. Sir William Niven was a Fellow 
of the Royal Society, and President of the Mathematical 
Society 1908-1909. He left Cambridge in 1882 and 
became Director of Studies at the Royal Naval College, 
Greenwich. He held this post until 1903, when he 



retired at the age of sixty, and received the K.C.B. for 
his official services. He died at Sidcup in 1917. 

The lectures given by J. W. L. Glaisher on pure mathe- 
matics were the most interesting I ever attended on that 
subject ; indeed he made me at one time quite enthusiastic 
about elUptic functions. The lectures were very clear and 
he covered a good deal of ground ; above all, they were 
never dull and were very human. If he was talking about 
a theorem discovered by X he would break out with “ X 
was a great mathematician but he was a queer fish. When- 
ever he was introduced to a pretty girl he would, when he 
went home, write a sonnet about her and send it to her ’’ ; 
or of Y, “ He once stabbed a man and there was the 
dickens of a row This gave a certain hveliness to his 
lectures which was not conspicuous in those of some of 
his contemporaries. The dullness of some of these can 
hardly be imagined. One of them adopted a method which 
I have never seen before or since. He hardly spoke a word 
but wrote steadily on the blackboard ; when he had filled 
it he said, “ Copy that I ” While we were doing this he 
was filling another board, and so the lecture went on. 
Glaisher's father was a well-known meteorologist who 
had gained great celebrity by making balloon ascents of 
record heights to take meteorological observations. Like 
his son he revelled in scientific societies, and his present to 
his son when he came of age was to pay the fees for life 
membership to the British Association, and to practically 
all the mathematical and astronomical societies whose 
membership could be obtained in this simple way. 
Glaisher was Second Wrangler in 1871, when John 
Hopkinson was Senior. He was then twenty-three years 
old. He was elected Fellow and Lecturer at Trinity 


College in the same year. Before he took liis degree he 
had had a paper pubhshed in the Transactions of the 
Royal Society, a most unusual thing for one so young. 
In 1871 he was put on a Committee of the British 
Association to report on mathematical tables. The other 
members of the Committee were Cayley, Stokes, 
WiUiam Thomson and H. J. S. Smith. This is very 
strong evidence of the high opinion which the leading 
mathematicians of the day held of his abihty. He 
knew all the mathematicians of his time and had 
heard what they said about their predecessors, so that 
he knew a good deal more about mathematicians than 
their achievements in mathematics. During the seventies 
and eighties he was the most active promoter of research 
in pure mathematics in Cambridge ; he was the editor of 
the Quarterly Journal of Mathematics, in which much of this 
appeared. The conspicuous success in recent years of the 
Cambridge School of Pure Mathematics is due in no small 
degree to the spadework done by Glaisher more than 
fifty years ago. 

In 1883 he accepted the offer of a tutorship in Trinity 
College. This was a most unfortunate decision- As a 
tutor he was subject to continual interruption wliich 
very seriously interfered with his mathemetical work, 
and when on Cayley’s death in 1895 the Sadleirian 
Professorship in Pure Mathematics became vacant he 
was not elected. As his lectureship in mathematics 
at the College also ran out at about the same time, he 
badly wanted some other work to fill the gap and took 
to collecting china and pottery, and this became the chief 
interest of the last thirty years of his hfe. His original idea 
was to make a collection which would illustrate by early 
specimens the introduction of each step in the improve- 



ment of the techniq[ue of the potter’s art. In this I under- 
stand he succeeded, but in doing this he had got bitten 
with the collector’s mania, and became specially interested 
in “ shp ware ” and was anxious that his collection of this 
should be the best in the world. This is a very dangerous 
state of mind, for whenever an exceptionally fine specimen 
comes on the market you feel you must buy it or one of 
your rivals will get ahead of you. Glaisher spent a very 
large amount on his collection, considerably over 100,000 
I beheve, but he used to say that he had never regretted 
any of his extravagances, but had often been sorry for many 
of his economies which made him let a piece go which 
afterwards he was always longing to possess. He left 
his magnificent collection to the Fitzwilham Museum : a 
beautifully illustrated catalogue made by Mr Rackham 
has just (1935) been issued. These will keep his memory 
green and give, as he would have wished, pleasure to many 
in the years to come. He was awarded the Sylvester 
Medal by the Royal, and the De Morgan Medal by the 
Mathematical Society. He had been President of many 
Societies, the Cambridge Philosophical, the Mathematical, 
the Astronomical, the Cambridge Antiquarian, and of the 
Cambridge University Bicycle Club, for he was in the 
early days of cycling an enthusiastic rider of the old 
“ penny-farthing ” machine. I think, however, the office 
which gave him the greatest pleasure was the Presidency 
of the Astronomical Club, which he held for thirty-five 
years. The Club is famous jfbr good fellowship and good 
dinners. It is the custom of the Club for the President to 
propose the health of every guest at these dinners. By all 
accounts he did this with great success. Certainly the few 
speeches I heard were quite dehghtful, full of that humour, 
kind but discriminating, which was characteristic of the 



man. Though he was a bachelor, a don, and had Hved 
in College rooms for more than sixty years, he was by 
no means a recluse ; in fact he was very fond of talking, 
and keenly interested in the affairs of his friends and 

While I was an undergraduate I attended lectures given 
by Professors Cayley, Adams and Stokes. The first set 
of Cayley’s lectures I attended were somewhat remarkable. 

I was the only imder graduate ; Glaisher and R. T. Wright, 
both Masters of Arts, made up the audience. Cayley did 
not use a blackboard, but sat at the end of a long narrow 
table and wrote with a quill pen on sheets of large foolscap 
paper. As the seats next the Professor were occupied by 
my seniors, I only saw the writing upside down. This, 
as may be imagined, made note-taking somewhat difficult. 
I should, however, be very sorry to have missed these 
lectures. It was a most interesting, valuable and educa- 
tional experience to see Cayley solve a problem. He did 
not seem to trouble much about choosing the best method, 
but took the first that came to his mind. This led to 
analytical expressions which seemed hopelessly com- 
pHcated and uncouth. Cayley, however, never seemed 
disconcerted but went steadily on, and in a few lines had 
changed the shapeless mass of symbols into beautifully 
symmetrical expressions, and the problem was solved. 
As a lesson in teaching one not to be afraid of a crowd of 
symbols, it was most valuable. 

Professor Adams, whose lectures I also attended, never 
seemed to have any compHcated collections of symbols 
to deal with ; he, Hke Kirchhoff, carried the feelings of 
an artist into his mathematics, and a demonstration had to 
be elegant as well as sound before he was satisfied. His 



lectures were wonderfully clear, and were read from 
beautifully written manuscript which he brought into 
the lecture-room in calico bags made by his wife. The 
lectures I attended were on his own researches on Lunar 
Theory. They had never b^en published and contained 
important additions to that theory. I tliink, however, 
reading a lecture deprives it of much of its charm : the 
reader is apt to be bored ; his mind is not so alert as if he 
had to frame his sentences as he went along, or rack his 
memory to reproduce them, and if he is lecturing to 
students he goes too quickly to allow them to take ade- 
quate notes. In particular, I think the dullest lectures are 
those read from the proof-sheets of a book which is 
passing through the press. 

The lectures I enjoyed the most were those by Sir 
George Stokes on Light. For clearness of exposition, 
beauty and aptness of the experiments, I have never heard 
their equal. He had only the simplest apparatus at his 
command, no light but that of the sun, no assistant to help 
him. He prepared the experiments himself before the 
lecture and performed them himself in the lecture, and 
they always came off. His success was not obtained with- 
out much labour. His daughter, Mrs Humphry, in her 
biographical sketch prefixed to the Memoirs and Scientific 
Correspondence of Sir G. G. Stokes, edited by Sir Joseph 
Larmor, tells how preoccupied he was in the May Term 
not only with the experiments but also with the form of 
his lectures. EQs dependence on the sun obliged him to 
make hay while it shone, so that on bright days his lectures 
lasted far beyond the canonical hour. I remember on 
one occasion, long after my attendance at his lectures and 
when he was well over eighty, I met a batch of very 
hungry-looking students coming into the Cavendish 



Laboratory one afternoon at half-past two. I asked them 
what they had been doing, and they said they had just 
come from Sir George Stokes’ lecture which had com- 
menced at twelve. 

Like his predecessor in the Lucasian Chair, Sir Isaac 
Newton, he made his remarkable discoveries in optics 
working in his rooms m College with very simple appara- 
tus. Though Stokes was such an accomphshed lecturer, his 
power of keeping silent was equally remarkable. He, like 
Newton, represented Cambridge University in Parha- 
ment : he was member for four years and attended the 
House with great regularity, but never spoke. It is reported 
of Newton, who was member for two years, that the only 
time he addressed the House was to move that a window be 
opened, and Sir Joseph Larmor, another Lucasian Professor, 
was member for about eleven years and only spoke 
once, so that the Lucasian Professors cannot be accused of 
having wasted the time of the House. Stokes certainly 
had not much small-talk. (A story is current in Cambridge 
that a visitor, who did not know that it was Lady Stokes 
she was speaking to, said, “ There are two men in Cam- 
bridge whom it is positively painful to sit next at dinner : 
they never say a word ”. Lady Stokes said, “ Yes, George 
is one, but who is the other ? ” He was, however, quite 
ready to talk on subjects on which he felt he had some- 
thing to say. I once saw an amusing instance of this. He 
was sitting at lunch next a very charming American lady 
who started one subject after another without getting any 
reply but yes or no. At last in desperation, she asked him 
which did he hke best, arithmetic or algebra ? The change 
was marvellous ; he became quite fluent and talked freely 
for the rest of the lunch. | 

He was quite ready to talk on scientific subjects, and a 

49 E 


talk with him left one wiser than before. He had a mind 
which, like a filter, seemed to clarify anything which 
passed through it, and one's ideas seemed always clearer 
and more definite after a talk with him about them. He 
was also very open-minded. When one presented to him 
a new idea, he did not at once say there could be nothing 
in it, but would hsten quite patiently to anything one might 
say in its favour. He was, however, exceedingly cautious 
about coming to a conclusion. But, if he made any 
criticism, one was quite sure that it would be wise to recon- 
sider most carefully the point he criticised before commit- 
ting oneself to it. He had the Newtonian type of mind 
to a remarkable extent, but he was even more cautious 
than Newton. One might conceive his having written 
the bulk of Newton’s Optics but not of his venturing to add 
the celebrated queries. It was very interesting to see Lord 
Kelvin and Stokes together. Lord Kelvin regarded Stokes 
as his teacher and always had the greatest respect for his 
opinion, and often said when he came to a difficulty on some 
mathematical or physical problem, “ I must ask Stokes 
what he thinks about it The temperaments of the two 
were, however, very different. When Kelvin was speak- 
ing, Stokes would remain silent until Kelvin seemed at 
any rate to pause. On the other hand, when Stokes was 
speaking, Kelvin would butt in after almost every sentence 
with some idea which had just occurred to him, and which 
he could not suppress. I once saw a curious reversal of this. 
They had come together to the Cavendish Laboratory, and 
I was showing them some experiments I was engaged with 
at the time, on the electric discharge through gases. I 
happened to speak about atoms playing a part in one of the 
effects I was showing, when Kelvin said he did not beheve 
in atoms but only in molecules. This was too much for 


Stokes. He began at once to give a charmingly clear 
account of the reasons why atoms as well as molecules 
must exist. He was so much in earnest that Kelvin for 
once could not get a word in edgeways : as soon as he 
started to speak, Stokes raised his hand in a solemn way 
and, as it were, pushed Kelvin back into his seat. 

Stokes was one of the Secretaries of the Royal Society 
for thirty-one years, and the work he did in this capacity 
had a very great effect on the progress of the physical 
sciences. He read all the mathematical and physical 
papers sent in to the Society with great care, suggesting 
improvement in the experiments, or in the arguments, or in 
the method of presentation. In addition to his work on 
the papers sent in to the Royal Society, he was in constant 
correspondence with many of the most active workers on 
physics, such as Crookes, Warren de la Rue, Smithells. 
These, as his correspondence and their acknowledgments 
show, often turned to him for advice. He was the guide 
as well as the teacher of his contemporaries. This work 
left him with but little time for his own researches. He 
had not had time to make any progress with the textbook 
on Hght which students had expected and hoped for for 
more than thirty years. Stokes, Uke Newton, was deeply 
interested in theology and spent much time in the latter 
part of his Hfe in correspondence about his doctrine of 
“ Conditional Immortality He held that only the sotils 
of those who had been righteous in their life, or who had 
repented before their death, were immortal. The souls 
of the wicked vanished : there was a Heaven but no Hell. 
Some have regretted that he “ wasted on reUgious sub- 
jects so much time that might have been spent on scientific 
ones. It should be remembered, however, that his scale 
of values was probably different from that of his critics. 



He was a deeply religious man, and to Hm as to many others 
the orthodox view about Hell and eternal torment seemed 
incompatible with the spirit of Christianity. He thought 
this was because “ reHgious people insisted on a slavish 
literalism ”, “ framed a theory that the Bible must be inter- 
preted in a way just like that in which a lawyer would in- 
terpret an Act of Parliament, stuck to the letter rather than 
attempted to catch the spirit He would have regarded 
time spent in clearing away obstacles to his own faith or in 
helping others to do the like, not as time wasted but as used 
to the best advantage. 

“ Conditional ImmortaHty ” did not get much support 
from Ecclesiastical Authorities and was, I beheve, some- 
times attacked from the University pulpit. Though a 
strong conservative in many things, he held hberal opinions 
about Church matters. He wished the compulsory sign- 
ing of the Thirty-nine Articles to be aboHshed and the 
Athanasian Creed to be altered. 

He was a pioneer in Cambridge in using a typewriter, 
much to the rehef of his friends, as his handwriting was 
very shaky and somewhat difficult to read. It was, how- 
ever, legibihty itself compared with that of another Pro- 
fessor, whose letters took the spare time of many days to 

My undergraduate days were very pleasant though 
uneventful. The most exciting incidents were perhaps the 
results of the annual College Examinations, and the migra- 
tion for the Long Vacation term from my lodgings in 
Malcolm Street to rooms in the Great Court. In those 
days many more undergraduates came up for the Long 
Vacation and stayed up longer than they do now. Most 
men who were serious candidates for honours came up at 



the beginning of July, and stayed up to nearly the end of 
August. More than 200 came up then ; now there are 
not much more than half that number, and they do not 
stay up so long. It was very pleasant : we had more leisure 
as there were no College lectures, though the mathema- 
ticians went to Routh, and more opportunities of making 
friends. It was too, from the educational point of view, 
an important part of our stay in Cambridge. We had 
time to think, and to arrange and co-ordinate our know- 
ledge. We got a better grip of our subject and were able 
to work out any new ideas we might have. An important 
event of the Long was the cricket match between members 
on the Foundation, i,e, the Fellows and the Scholars, and 
the rest. As at that time about half the members of the 
Cambridge eleven were Trinity men, there was generally 
a ‘‘ blue ” playing. There were, of course, some who 
never played cricket except at this match. It was an 
amusing match to watch. There was one classical Fellow 
of the College who was so anxious to make runs that he 
usually ran two or three of his side out in the attempt. 
The only fly in the ointment was that we had to keep ” 
three morning Chapels at 7.30 each week. This was more 
diflScult than it looks, for sometimes though we got up 
early it was not quite early enough, and the Chapel doors 
were shut before we could reach them. 

When I was in residence in the Long of 1879 the most 
severe thunderstorm I have ever seen struck Cambridge. 
It was on a Saturday night and Sunday morning : the 
storm had been going on for some time before I awoke, 
and when I looked out of the window the Great Court 
was a lake some inches deep ; torrents of rain were falling 
from the skies and pouring from the roofs into the Court. 
I looked at the river before going into Chapel on Sunday 



morning ; it was very high and rising rapidly, and when 
we came out it had overflowed its banks and the Paddocks 
on each side of the Avenue were flooded. It was many 
days before the water subsided from them, and there was 
fishing for small fish available for ardent anglers. 

Another institution which was in force in my time, 
but which I am sorry to say has now disappeared, was 
“ The Scholars’ Table ” ; one table at the diimer in Hall 
was reserved for scholars. They need not sit there unless 
they liked, but a large proportion of them did so. It was 
very enjoyable and gave excellent opportunities for making 
friends with men of other years and studying other sub- 
jects. T. E. Scrutton, a man in my own year who became 
Lord Justice Scrutton, dined regularly at this table. We 
all felt sure he would succeed at the Bar, he was so fond 
of arguing and so quick-witted, and so able. He got a 
First-Class in the Moral Science Tripos and was Senior 
in the Law Tripos. Later on he won the Yorkc Prize on 
four occasions : two of the essays which won this prize, 
those on Charter Parties and on Copyright, ^^velo^ed 
the standard books on these subjects. ( He was a mment 
figure at the Union and became President, and was very 
successful in scoring offhis opponents. When one of these 
had finished a long string of abuse by calling the other side 
“uncircumcised Philistines”, Scrutton at once jumped 
up and began, “ My honourable and I suppose circumcised 
friend”. ) 

Another man in the same year was H. H. West, 
a classical scholar, an Irishman, full of wit, immensely 
entertaining and a good actor. He gave on occasions 
representations of some of the figures in Smitli’s Dictionary 
of Classical Antiquities : his star turn was that of the man 
with the testudo. He took a leaf out of his table and, 


after taking off his clothes, put it on his back and gave a 
screamingly funny performance. 

Another scholar of the same year was G. M. Edwards, 
a very good classic who was elected Fellow and Lecturer 
and afterwards Tutor of Sidney Sussex College. Another 
was Claud Melford Thompson, who was the first to win 
marks of distinction in both Physics and Chemistry in 
Part II of the Natural Sciences Tripos. He was for many 
years Professor of Chemistry in the University of Cardiff 
and took a prominent part in the administration of that 

W. H. Whitfeld, a mathematical scholar in the same 
year, applied his mathematics to whist and succeeded 
“ Cavendish ’’ as Card Editor for the Field. He had an 
amazing card memory. I often played two or three 
rubbers with him after Hall, and I have known him, when 
I had been his partner, come round the next morning and 
tell me that if I had played another card instead of the one 
I had we should have won two more tricks. He took up 
a pack of cards and without any hesitation laid out the hand 
as it was when the wrong card was played. I of course did 
not remember more than a fraction of the cards, but the 
few I did remember agreed with his placing. He spent a 
great amount of time on the mathematics of whist, and 
by dealing out countless hands had accumulated a vast 
amount of material on how far the distribution of cards 
in actual play differed from that predicted by the Theory 
of Probabihty . By the advent of Bridge this had lost much 
of its interest and it was never, as far as I know, published. 

G. W. Johnson, a scholar in the same year, took a 
Double First and went into the Civil Service and was for 
many years Chief Clerk in the Colonial Office. Another 
Double First had been obtained by E. V. Arnold, who 



was in the year above. He was bracketed Senior Classic 
and was also a Wrangler : he was a man of great energy 
and took a very active part in starting the Cambridge 
Review, He became Professor of Latin in the University 
of Bangor. 

The Mathematical Tripos 

The examination for the Mathematical Tripos when I 
sat for it in January 1880 was an arduous, anxious and a 
very uncomfortable experience. It was held in the depth 
of winter in the Senate House, a room in which there were 
no heating appliances of any kind. It certainly was 
horribly cold, though the ink did not freeze as it is re- 
ported to have once done. The examination was divided 
into two periods : the first lasted for four days. In the 
first three days we were examined on the elementary 
parts of geometry, conic sections, algebra and plane 
trigonometry, statics and dynamics, hydrostatics and 
optics, Newton and astronomy. Five papers were set on 
these subjects, each paper containing about twelve ques- 
tions, each question consisting of a piece of book work 
and a rider which was a question, not supposed to be taken 
from a book, but one whose solution was closely con- 
nected with the piece of book work with which it was 
associated. In addition to these five book-work papers, 
there was a paper called the problem paper in which there 
was no book work. The questions were in themselves 
generally a htde more difficult than the riders in the 
book-work papers, and, what was more important, you 
were deprived of the guidance given by their association 
with a particular piece of book work. In the papers set 
in the first three days you were not allowed to use 


October Tenn, iSycj. 

right ; {Sack roiu') ; J. W, Wclsforti, Joseph 


the methods of the differential calculus, or of analytical 
geometry. The fourth day was a recent introduction 
dating from 1873. The two papers set on this day included 
easy questions on the higher parts of pure and applied 
mathematics, and also on the physical subjects — heat, 
electricity and magnetism—which had been introduced 
into the Tripos at the same time. An additional examiner 
was also appointed, specially qualified to deal with these 
subjects. The first of these examiners was Clerk Maxwell. 
On the fourth day the use of the differential calculus and 
analytical geometry was allowed. The papers in the 
morning were from 9 to 12, those in the afternoon from 
1.30 to 4. At the end of the fourth day there was an 
interval of ten days in which the examiners drew up a list 
of those who, by their performance on the first three days, 
had acquitted themselves so as to deserve mathematical 
honours. These, and these only, could take the second 
part of the Tripos, which lasted for five days beginning on 
the Monday next but one after the beginning of the first 
four days. The marks allotted to the last five days were 
about six times those for the first four. The questions 
ranged over all branches of mathematics and there were 
two problem papers. The questions set on the first two 
days of this examination were on the parts of mathematics 
which had been included in the Tripos almost since its 
foundation, and were subject to the restriction that the 
book-work papers set in the first two days of the ex- 
amination should not contain more questions than a well- 
prepared student might be expected to answer in the 
allotted time : this did not apply to the papers set after 
the second day. As each paper contained twelve ques- 
tions and each question consisted of two parts, a piece of 
book work and a rider, this was pretty good going, but 



I believe that a few men each year did get a large percentage 
of the maximum marks obtainable on these papers. They 
knew the shortest proof for each piece of book work that 
was set ; they had written it out over and over again ; 
they had not to think about it, but merely write as fast as 
they could. The riders were a greater difficulty, but in 
the textbooks numerous “ examples ” were given for 
each piece of book work and they had probably done 
something very similar to the rider set in the paper. The 
details of the question, e.g, the algebraical work, was new, 
and it was of great importance that the student should make 
no sHps in this ; an error in arithmetic, or a wrong sign 
in a piece of algebra, would involve going through the 
work again, and a loss of time when there was no time to 
lose. Accuracy in manipulation was perhaps the most 
important condition in this part of the examination and 
the most difficult to impart : to err is human even in 

Another quality which played a great part was con- 
centration on the question in hand, and ability to get 
quickly into stride for another question as soon as one 
had finished with the old. These qualities, having one's 
knowledge at one’s finger-ends, concentration, accuracy 
and mobility owed their importance to the examination 
being competitive, to there being an order of merit, to 
our having to gallop all the way to have a chance of 
winning. These quaHties are just those which are of most 
importance at the Bar, and made the old Mathematical 
Tripos an excellent training for that profession. It is 
significant, I think, that the last Tripos to give up arranging 
the list in order of merit was the Law Tripos, which re- 
tained it until 1923 , forty years after it had been dropped in 
the mathematical. It is somewhat humiliating to compare 



the rate at which one could do mathematical problems 
when in for the Tripos, with the rate one can attain late 
in life. 

In the last three days of the Tripos, when no pretence 
was made that the questions could be done by well-pre- 
pared students in the allotted time, a much smaller percent- 
age of marks was the rule. The book work in the higher 
subjects took much longer, and the number of questions 
was only about two less than in the other parts ; indeed it 
would have been good going to write out the book work 
alone. The riders, too, took in general longer to write 
out, and since sometimes not more than one examiner was 
an expert in some of the new subjects, his papers were not 
subject to effective criticism from his colleagues, so that some- 
times the papers were absurdly difficult. I have heard of 
cases where not a single question in a long paper was com- 
pletely done by any of the candidates. This led to there 
being great gaps between the marks obtained by candidates 
coming next in order in the list. There was one famous 
case when the Senior Wrangler’s marks were considerably 
more than twice those of the Second Wrangler, who 
became a very distinguished mathematician and a Profes- 
sor in the University. From my experience as an examiner 
in both mathematics and physics, I have come to the 
conclusion that examinations in the highest parts of these 
subjects are unsatisfactory. In mathematics the pieces of 
book work are in general very long, and if the candidate 
makes a sHp in the analysis and does not get the result asked 
for, it may take him a long time to find out the error and 
correct it. I have known more than one case where a 
candidate, who later proved to be a very able mathemati- 
cian, sent up a paper in which not a single question was 
completely solved. When preparing for an examination 



one has to get up the subject in much greater detail than 
is necessary for understanding its scope, and the general 
methods used to obtain the results. Memory is burdened 
with a mass of detail which will very soon be forgotten. 
All that one need remember is where to look for them 
when wanted. The same considerations apply to examina- 
tions on the most recent discoveries in physics. In each 
case I think the student would benefit if, instead of spend- 
ing so much time in getting his knowledge up to examina- 
tion pitch, he spent some time in attempting a piece of 

Again, the questions set in mathematical physics often 
stop where the real interest begins. The question asked is 
often to find a relation between a number of mathematical 
symbols representing various physical quantities ; nothing 
is asked as to what are the physical consequences result- 
ing from this relation. This, however, is just the thing 
which is of interest to the physicist ; it is as if he 
received a message in cypher and made no attempt to 
decode it. 

The Tripos under the regulation I have described was, 
in my opinion, a very good examination for the better 
men. It was, however, a very bad one for the majority 
who had not exceptional mathematical ability. Many of 
these men could cope with the more elementary subjects 
and benefit by studying them, but with these they had shot 
their bolt ; they found the higher subjects beyond them 
and the time they spent over them wasted. Under the 
old regulations, if these men were to get any credit for the 
mathematics they did know, they must wait for the Tripos 
at the end of their tenth term, and for the last three or 
even more terms they were only marking time, not gam- 
ing any additional knowledge or any mental training. 



Under the new system the men can be examined in element- 
ary mathematics at the end of their first or second year, 
and can thus take up a new subject, such as engineering, 
economics or science, in which their mathematics may prove 
of considerable assistance. Whether or not the changes 
that have been made in the Mathematical Tripos have been 
instrumental in promoting the progress of mathematical 
science in this country is a question which it is very 
difficult to answer. There is no doubt that the number of 
mathematical papers pubHshed in England has increased 
very greatly, and so has the number of people engaged 
in research in mathematics, but this in my opinion is 
largely due to the great change which has come over the 
feeling in the country with regard to research, rather 
than to the changes in the Tripos itself. In the days 
of the old Tripos very few rewards were given for re- 
search. Fellowships, except at Trinity College, were 
given for success in examinations and not for research. 
Scholarships stopped as soon as the scholar had taken his 
degree. When a man applied for a teaching post the 
qualification which carried most weight was that of being 
a good teacher. No one asked whether he was a good 
researcher, or whether he had done any research at all. 
There were no rewards for research except the small 
number of professorships in the few universities which 
then existed. Now all this has been changed ; the country 
has got the research habit, research is the fashion in all 
subjects. Candidates for Fellowships would have little 
chance of election unless they submitted a dissertation con- 
taining an account of a piece of original research. For all 
scientific posts the predominant qualification is a successful 
piece of research. The student who, after taking his 
degree, wishes to research, may now get very substantial 



grants of money to support him while researching. These 
may come from his College in the form of research scholar- 
ships, from the university which awards studentships for 
research, from outside bodies like the Board of Invention 
and Research, which has made a great number of sub- 
stantial grants to enable students to continue their re- 
searches ; from the 1851 Commission and some of the 
great City Companies, to mention only the most promi- 
nent. There are thus many more students in the university 
engaged in researches, each of which ought to, and many do, 
result in the production of a paper worthy of publication 
in a scientific magazine or the Transactions of some scien- 
tific society. The great majority of these would not have 
been written unless the authors had received inducements 
and assistance which hardly existed fifty years ago. Then 
there were comparatively few men engaged in research, 
and those who were, did it not because public opinion 
expected it of them, but because of their enthusiasm for 
science and the joy they felt in discovery. They were 
exceptional men. Men of this type cannot be produced 
by giving scholarships or even by particular schemes of 
education. They are bom, not made ; and as experience 
has shown, they seem able to get to the front in spite of all 
obstacles. The “ mute inglorious Milton is probably a 
myth. Dr. RashdaU {Universities of Europe in the Middle 
Ages, vol. ii. pp. 2, 602) says that tire means of education in 
the Middle Ages were more widely diffused than is gener- 
ally supposed, and that “ except in remote and thinly popu- 
lated regions, a boy would never have to go very far from 
home to find a regular Grammar School Thus any 
boy of exceptional abihty might be expected to have come 
under the notice of someone who, like the old Scotch 
dominies, would set to work to raise funds enough to 



enable him to go to a university. Increase in the sum spent 
on education, improved methods of teaching, the provision 
of scholarships to the universities and the like, cannot be 
expected to increase to any great extent the number of 
quite exceptional men. They can, however, and do, in- 
crease the number of able men available for the service of 
the State, for our industries and for the promotion of 
science. They may be compared with improvements in 
telescopes which, while they do not reveal new stars of 
the first magnitude, which can be seen without them, do 
bring to hght multitudes of new worlds. 

I took the Tripos Examination in January 1880. The 
thing about it which remains most clearly in my memory 
is that I suffered from a bad attack of insomnia during the 
last five days, and got very little sleep. Insomnia is even 
more unpleasant in Cambridge than in most other places, 
for since several clocks chime each quarter of an hour you 
know exactly how much sleep you have lost, and this 
makes you lose more. Though the nights were very un- 
pleasant I do not think they had much effect on my work 
in the examination, for when I got started on a paper the 
feeling of fatigue passed away. I had a shampoo between 
the morning and afternoon papers and got much sympathy 
from the barber, who said he was glad he was not in 
my shoes. I came out Second Wrangler ; Larmor was 
Senior. I was very well satisfied with the result, as I 
was quite as high up as I ever expected to be. I had a 
return of insomnia in the Smith’s Prize Examination and 
actually had a short doze in the afternoon paper at the 
Observatory. This may, however, have been due to the 
excellent lunch which Professor and Mrs Adams provided 
for us. 



Undergraduate Life Then and Now 

I ceased to be an undergraduate in 1880. Looking 
back on my undergraduate days and comparing under- 
graduate life then with what it is now, I see of course many 
important changes but not, I think, such important ones as 
have occurred in many other walks of life. They are 
certainly far less fundamental than those in the lives of the 
dons, for hardly any of these were married when I was an 
undergraduate, while now but few are single. The advent 
of students from Newnham and Girton has made some 
difference. "We did not sit side by side with ladies during 
lectures, nor treat them to chocolate and cakes in the in- 
tervals between them, nor, except in May week, invite 
them to our rooms. These, however, are trifles compared 
with matrimony. Perhaps the most striking difference is 
in amusements and games. In those days there were no 
theatres open in term time. The Theatre Royal in Barn- 
well, a suburb of Cambridge, existed, but was only open 
during the Long Vacation. We find from Gunning's 
Reminiscences that it was regularly attended at the end of 
the eighteenth century during Stourbridge Fair, then one 
of the largest fairs in the country, by a group of Shake- 
spearian critics headed by Dr. Farmer, the Master of Em- 
manuel College. It had in my time grievously fallen from 
that high estate, and some of the interpretations of Shake- 
speare’s meaning would not have met with his approval. 

One year when we came up at the beginning of the 
October term, we found posters all over the town announ- 
cing that the Theatre Royal, Barnwell, would reopen on 
a certain day under entirely new management ; when the 
audience arrived they found diat instead of a play they 



were offered a prayer meeting. The theatre had been 
bought by the Hon. Ian Keith Falconer, who subsequently 
became Lord Almoner’s Professor of Arabic, and who was 
an ardent supporter of reHgious missions. He was also 
the champion bicychst of his time. The theatre was 
renovated and revived a few years ago as the “ Festival 
It produced many interesting plays which could rarely be 
seen elsewhere, and became an important feature in the 
social hfe of the University. 

The only plays to be seen at Cambridge in my days 
were one in the Michaelmas Term and another in the May 
Term, given by the A.D.C., a dramatic club founded by 
Bumand. These reached a very high standard. There 
was generally among the older members of the University 
someone who, like J. W. Clark in my time, took great 
interest in the theatre, and who spent a great deal of time 
and trouble over the rehearsals. All the women’s parts 
were taken by men, and I think the best Lady Teazle I 
ever saw was Mr Manners, a Jesus man. Some of the 
undergraduates who took part in these plays subsequently 
went on the stage, and one or two of them attained con- 
siderable success. The photographs in the rooms of the 
A.b.C. are very interesting. You see future Bishops as 
singing chambermaids and Cabinet Ministers as butlers. 
Things are changed now. There is a large theatre and 
another being built ; there are five or six cinemas ; there 
are several new dramatic clubs such as the Marlowe 
Society and the Foothghts, and every few years there is a 
Greek play. Thus each year several plays are produced, 
and a great deal of time and trouble is spent over them, 
and the work of the undergraduates taking part in them 
seriously interrupted. There was always much good 
music to be heard in Cambridge, but now the Cambridge 

65 F 


musicians are much more ambitious, and produce operas 
such as Purcell’s Faery Queen with large orchestras, and 
which involve a great sacrifice of time by those taking 
part in them. In addition to music there is dancing. This 
in my time was practically confined to a ball in the May 
Week ; now since there are so many more ladies resident 
in Cambridge, dances are going on all through term time, 
and besides private dances, there are dancing clubs, and 
dances for every conceivable charitable purpose. The 
result is that an undergraduate who is good at acting, 
singing or dancing gets Httle time for his studies in term 
time and has to rely on the vacations for his reading for 
his examinations. 

In those days, roughly speaking, the only games played 
by undergraduates were cricket and football ; lawn tennis 
had only just been introduced, and squash racquets was 
a long way ahead. There certainly was a golf-links at 
Coldham Common quite close to the town, but these I 
think were the most depressing and uninviting links I ever 
saw. So few played that a friend of mine who went 
there one afternoon and was knocking a ball about with 
a club, was seized upon by the Secretary and asked to play 
against Oxford the next day. A few played fives, or real 
tennis, at the courts in Burrell’s Walk or Tennis Court 
Road. The ordinary reading man who was not particu- 
larly good at games had not much chance of playing 
either cricket or football, for there were enough men who 
had got their colours ” at school to fill up the College 
teams — there was no room for the rabbits ”, A fair 
number of fireshmen joined their College boat club, where 
they found a good many companions who, like them- 
selves, knew very little about rowing. They went regu- 


larly in their first term down to the river to be tubbed. 
Rowing is not a very satisfactory way for the ordinary 
reading man to get his exercise. If he does not take it 
seriously enough to get into a College eight, he does not 
get enough exercise, while if he does get in he gets too 
much, and does not feel inclined for work in the evening. 
In those days the great m^ority of the reading men got 
their exercise by taking walks. Between 2 and 4 in the 
afternoon, streams of undergraduates, two and two, might 
be seen on all the roads within three or four miles of 
Cambridge, taking the Grantchester, Madingley, Coton, 
Cherryhinton or Shelford “ grinds On Sundays many 
went further afield and walked for five or six hours. Now 
there are many games which, like lawn tennis, golf or 
squash racquets, only require two players and for which it 
is generally possible to find an opponent nearly as bad as 
yourself, so that you need not feel you are spoiling any- 
one’s game. Even in football, hockey or cricket, there are 
many clubs which cater especially for poor players, so that 
now very few undergraduates take walks. I found these 
walks very pleasant ; the scenery round Cambridge is 
much better than most people imagine. Besides, if you 
keep your eyes open there are beautiful things to be seen 
in any walk in the country, and even in one in a town. I 
think it is a great pity that children both at home and at 
school are not encouraged to look out for beauty around 
them. If they once got the habit it would a be continual 
source of pleasure to them. Most people nowadays 
hardly recognise beauty unless it is pointed out to them, 
and will go miles to see something which figures on a 
picture postcard, while more beautiful things are to be 
found close by them. The “ model villages ”, the “ fairy 
glens ”, the “ pretty comers ”, the “ lover’s leaps ” of the 



picture postcards, might all go without diminishing by 
more than, an infinitesimal fraction the beauty of the 
country. The walks and the long talks which accom- 
panied them, were an excellent means of making friendships 
more intimate. The solitude a deux is, I think, much better 
for this purpose than playing games, or going to meetings 
to hsten to essays or discussions. 

One very great friend of mine with whom I often 
took such walks was J. C.Watt, who had come up to 
Trinity from Glasgow University, where he had been 
a pupil of Sir Wilham Thomson. After staying two 
years at Trinity he migrated to Jesus College ; he was 
elected to a Fellowship there in i88i, and to a lectureship 
in 1883. He never married, but lived in College until 
his health broke down a few years before his death in 


He possessed to a degree I have never seen surpassed 
the power of winning the confidence of undergraduates. 

He welcomed them to his rooms, took great interest 
in what they were doing, and knew all about their suc- 
cesses in games, for he rarely missed an important cricket 
or football match. This put them at their ease, and helped 
to reveal to them his kindliness, which was the secret of 
his success. 

They felt that they had in him a real friend to whom 
they could go if they got into difficulties, even when these 
were due to their own silliness. They did so, and dis- 
closed what they had done with a frankness much greater 
than most of them could have done to thek own fathers. 
He began by teUing them very frankly what he thought 
of thek conduct, and then set to work to try to help 

Many Jesus men who were up between 1883 and 1928 


owe much to the help they got from “ Tommy ” "Watt, 
as he was always called. 

A great change in the relative popularity of different 
games has occurred since I was an undergraduate. Then 
the Rugby football matches were played on Parker’s 
Piece ; there was no charge for admission, and the attend- 
ance was not a tenth of what it is now when the Uni- 
versity has a fine ground of its own, where the gate money 
puts the finances of the Rugby Club into such a satisfactory 
position that it not only makes generous donations to 
support clubs in other sports, but has actually founded a 
lectureship in Classics in the University. On the other 
hand Fenners, the University cricket-ground, is now almost 
deserted, unless the match is with the Austrahans or teams 
from India or the Dominions. Then there would be a 
ring three or four deep round the ground at every match 
in the May Term. The pavilion was crowded with dons ; 
you were pretty sure to see there Munro, the great classic ; 
Aldis Wright, the Hebrew and Shakespearian scholar ; 
James Porter, the Master of Peterhouse, accompanied by 
his dog, for which he had paid the fee for life membership 
of the Cricket Club, so as to quiet his conscience about 
breaking the rule that dogs were not admitted to the 
ground ; Ward of Magdalene, a very stout man who was 
distinguished from his brother, one of the protagonists of 
the Oxford Movement, by being called the real presence, 
and his brother the ideal presence. 

Munro took great interest in cricket and, as he was a 
Trinity man, liked to have that College well represented 
in the Oxford and Cambridge cricket match. I remember 
one morning going into the Combination Room in 
College to read the newspapers ; the only person in the 
room was Munro, who was reading The Times. I had 



not met him before and he looked very disappointed when 
he saw me. It was evident there was something he wanted 
to talk about very badly. I sat down and began reading 
the paper. After a minute or two Munro could stand it 
no longer. He dashed The Times with quite a bang on 
the floor and said, “ What do you think that fellow 
Verrall’s done ? ” (A. W. Verrall was a distinguished 
lecturer in Classics in die College.) I said I did not know. 

“ Well/’ he said, “ he’s ploughed Foley for entrance to 
the College (Foley was a boy who had made a century 
in the Eton and Harrow match), and how do you think 
Verrall translates ? ” Here he went off with a piece of 
Greek, and gave Verrall’s translation. I tried to look as 
shocked as I could, and he went on, “ I don’t know what 
this College is coming to, when a man who makes 
mistakes like these in a straightforward piece of translation 
is allowed to plough a boy like Foley ”. 

Cambridge cricket was then at its zenith. Edward 
and Alfred Lyttelton, D. Q. and A. G. Steel, A. P. Lucas 
and Ivo Bligh all played for Cambridge between 1876 and 
1880. Edward Lyttelton was captain the year he took the 
Classical Tripos, and used to bring his books to Fenners 
and read while his >side was batting. The most decisive of 
the few defeats suffered by the first Australian team to 
visit the country was that inflicted in 1878 by Cambridge 
University, and on their second visit in 1882 they were 
again defeated by Cambridge. 

In those days blues ” were given only to those who 
represented Cambridge in the boat race or the cricket 
match : no blues were given for football. Oxford, 
however, gave ‘‘ Rugger ” blues in 1884. The Cambridge 
Rugby team was naturally up in arms, and said that if 
blues were not given to them they would take them. 



This brought all the wigs on the green, and in 1885 a 
meeting, to which all members of the University were 
admitted, was held in the rooms of the ‘‘ Union ”, the 
largest undergraduate club in Cambridge, to ascertain the 
feeling of the University. My old friend Richard Threl- 
fall, of whom I shall have more to say later, who had twice 
played in the Rugby team against Oxford, was selected to 
plead the case for the “ blue ” for the Rugby team. I 
went with him to the meeting, and though we arrived a 
few minutes before it was timed to begin, the room was 
so packed that he could not get through the crowd at the 
back of the hall, and he had to be held up by a few of his 
friends, of whom I am proud to say I was one, while he 
made his speech. The speakers before him were against 
the proposal, and deUvered carefully prepared speeches 
which smelt very strongly of the lamp and left the audience 
quite cold ; when he got up and jerked out from his un- 
comfortable stance one short sentence after another full of 
good sense, good humour and good jokes, he soon had 
the house rocking with laughter, and put the issue beyond 
doubt, I never heard a speech which had so much in- 
fluence upon the division. 

The views held by undergraduates as to what is good 
form change almost as frequently as the fashion of ladies’ 
dresses. In my time and for many years afterwards it was 
considered the height of indecency to carry an umbrella 
when wearing cap and gown, indeed our tutors warned us 
against it at their first interview. I have hved to see a time 
when it was considered to be indecent to be without an 
umbrella when you were out of doors, whatever other 
garments you might lack. The correct way of wearing 
it was not to have it rolled up neatly, but baggy like 
Mrs Gamp’s : it was not used as a walking-stick but carried 



gingerly in front, without touching the ground. Now 
again the umbrella has, for a time at least, retired to the 

Since the advent of Newnham and Girton students, 
undergraduates’ dress has been influenced by the necessity 
of preserving an adequate distinction between male and 
female attire and behaviour. j^In the days when the “ Eton 
crop ” was in fashion with Girton and Newnham students, 
a Trinity undergraduate with rather long hair called on his 
tutor. As he was going away the tutor said : “ If I were 
you I would get my hair cut ”. “ Oh, sir,” said the under- 

graduate, “ I should not like to do that, short hair is so 
effeminate.’y Since cigarette-smokmg has become so usual 
with women it has lost favour with undergraduates. The 
proportion of non-smokers to smokers among Trinity 
undergraduates is far greater than it used to be and is, I 
think, greater than that at Newnham or Girton. If the 
fashion for women to wear trousers extends to these 
Colleges our undergraduates will be driven to kilts. 

The modem undergraduate is more businessHke than 
we used to be, and more careful to get good value for his 
money. My tailor tells me that they now nearly always 
ask the price of a suit before ordermg it, while fifty years 
ago this was very unusual. Ready-money transactions 
are much more usual, surprisingly so, considering the readi- 
ness with which tradesmen give credit to undergraduates. 
A century ago Cambridge tailors had a peculiar system of 
insurance against losses from xmpaid bills. My father-in- 
law, Sir George Paget, told me that a College friend of his 
went down without paying his tailor’s bill. He got a post, 
and in about four years had made enough money to enable 
him to pay his debts. He came up to Cambridge to do so, 
went to his tailor and said he wanted to pay his bill. The 



tailor said, Sir, I could not think of taking the money ; 
we make it a rule when a gentleman has been down for 
three years without paying his bill, to distribute the amount 
he owes us among the bills of our other customers I 
got an illustration of the change which had come about, in 
a conversation I had with a bootmaker early in this century. 
I said I hoped trade was good. “No, sir,” he said, “ it is 
not. Things are very different now from what they were 
when you were an imdergraduate. Y ou will hardly beheve 
me, sir, when I tell you that I have not met what I should 
caU a really extravagant gentleman for more than three 

years.” “ Well, Mr ,” I said, “ what would you call 

an extravagant gentleman ? ” “ Sir,” he said, “ I should 

call a gentleman extravagant if he had more than two 
pairs of boots a week.” 

When I was an undergraduate the great majority of 
Cambridge men, after taking their degree, went into one 
or other of the professions, the Church, the Bar, Civil 
Service, Medicine or schoolmastering. Very few went 
into business, and those who did generally went into firms 
with which they had some family connection ; this is now 
changed, and more go into business than to the professions. 
This is because those at the head of large business concerns 
attach much greater importance than they used to do to 
a university education, and are willing to give, without the 
payment of a premium, a trial to those who have done well 
at Cambridge. In my time Cambridge men, after taking 
their degree, had to find a post for themselves ; there is 
now an important branch of the University called the 
Appointments Board, which has offices and a permanent 
staff in Cambridge, and has the advice of a committee 
consistmg of some of the men most influential in our m- 



dustries, finance and education. An old colleague of mine 
at the Cavendish Laboratory, now Sir Napier Shaw, F.R.S,, 
had a great deal to do with its formation. Under the 
guidance of its first secretary, H. A. Roberts, it gained the 
confidence of the employers ; he took great pains to get 
rehable information about the appHcants for employment ; 
he acted more like a judge than an advocate, and when he 
recommended a man, would mention his weaknesses as well 
as his merits. The result of this was that from small 
beginnings the Department rapidly increased ; in the last 
Academical year 193 5-36 it found posts for 596 men. These 
posts are of all kinds, financial, engineering, chemical, 
professorial, scholastic, secretarial, and most of our under- 
graduates who want employment after they leave the 
University send in their names to the Appointments Board. 

The increase in the number of provincial universities 
and schools of technology as well as in that of the pro- 
fessors, readers and lecturers in the older universities has 
provided a much larger number of academic posts. The 
attraction of these has drawn in many who would other- 
wise have become schoolmasters, especially those who have 
taken high honours. 

The greatest change, however, has been in the number 
of men who take Holy Orders, Of the 909 under- 
graduates who entered Trinity College in the years 
1920-24 inclusive, and whose names are on the books 
of the College, only 24 have done so, and all the indica- 
tions point to a further decrease in this proportion. 



Cambridge^ 187^-1884 

A FTER taking my degree I began the preparation of a 
zJL dissertation to be sent in for the Fellowship Examina- 
JL V. tion. The idea on which this was based had occurred 
to me before I came to Cambridge (see page 21), but I 
had not, while preparing for the Tripos, had time to develop 
it. It had to do with the nature of energy. According to 
the views then prevalent there were many different forms 
of energy. There was kinetic energy, that due to the 
motion of mass ; potential energy, that due to the position 
of a body amid various surroundings ; thermal energy, 
that possessed by a hot body in virtue of its temperature ; 
electromagnetic energy, that in electric and magnetic fields ; 
energy of chemical separation, that Hberated when two 
different substances, e.g. coal and oxygen, combine and 
give out heat. Energy of one kind could be converted 
into that of another but there was always a fixed rate of 
exchange, t.g. if a certain amount of kinetic energy were 
converted by friction into heat, the thermal energy 
developed would be strictly proportional to the amount 
of kinetic energy lost ; or, comparing different kinds of 
energy with different currencies, if all kinds were estimated 
on a gold standard the principle of the conservation of 
energy asserts that their total amount could not be altered 
by any physical process. The passage of energy from one 
form to another was called the transformation of energy. 
The view that energy itself could be of quite different 


kinds had always seemed to me to lead to great dfficulties 
when one tried to form a mental picture of what was going 
on when one kind of energy was transformed into another, 
and that a much simpler view was to suppose that energy 
was all of one kind and that the transformation of energy 
could be more appropriately described as a transference of 
energy from one system to another, the physical effects 
produced by the energy depending on the nature of the 
system in which it finds a home. My dissertation was of 
the view that all energy was kinetic energy. Very general 
methods for dealing with systems possessing only kinetic 
energy have been developed by Lagrange and Hamilton 
and are expressed by the Hamiltonian and Lagrangian 
Equations ; my dissertation was the application of these, 
and especially the Lagrangian ones, to various problems in 
physics and chemistry. This led to interesting relations 
between various physical effects which must be true what- 
ever may be the kind of mechanism which produces the 
effects. For example, if magnetising a bar of iron alters 
its length, altering its length will alter its magnetism, and 
if the amount of one of these effects is known, that of the 
other can be calculated. Again, if a property varies with 
the temperature, e,^. if the stiffness of a spring depends on 
its temperature, pulling out the spring will alter its tem- 
perature and the alteration in temperature will be such as 
to make it more difficult to pull it out. Thus if the spring 
is stiffer when it is cold than when it is hot, pulling out the 
spring will cool it, while if it is stiffer when hot than when 
cold, puUing it out will heat it. The general principle is 
that the alteration in temperature produced by any change 
in the system is that which will increase the resistance to 
that change. This principle was published independently 
and almost simultaneously by Le ChateHer. The disserta- 


CAMBRIDGE, 1879-1884 

tion was published, in an expanded form in two papers in 
the Transactions of the Royal Society, and was the founda- 
tion of my book Applications of Dynamics to Physics and 

In those days candidates in mathematics for a Fellow- 
ship at Trinity, besides sending in a dissertation, had to 
take an examination in which there were two mathematical 
papers and another paper on a subject (not mathematical) 
chosen by themselves, I had a peculiar experience with 
regard to the subject I chose for this paper. My first 
choice was Marshall’s Principles of Political Economy, as I 
thought that perhaps my mathematics might help in that ; 
but when I found that on almost every page general laws 
in large print were stated on what seemed to me very in- 
sufficient evidence, I thought I had better try something 
else, so I changed over to Kant. I don’t suppose I really 
understood it, but I enjoyed reading it and found it much 
more satisfactory than the Political Economy. I was for- 
tunate enough to be elected to a Fellowship at my first 
attempt, to the great surprise of my tutor, hi the interval 
between the end of the examination and the announcement 
of the result I met him in the Great Court and he said. 
What are you doing here at this time of the year ? ” I 
said I had just been in for the Fellowship Examination. 
He said, “ That is just like you, Thomson, never asking 
my advice. If you had come to me in the May Term I 
could have told you that there are two Senior Classics 
having their second try and a very strong Science candidate 
having his third and last, and there is not the sHghtest 
chance of their taking a candidate at his first try. You 
could then have enjoyed yourself in the Long Vacation 
instead of wasting your time over the Fellowship.” I was, 
however, lucky enough to be elected. 



In those days a Fellow did not enter into all his privileges 
and emoluments until he became a Master of Arts ; he 
could not dine at the High Table and only received two 
thirds of a Fellow’s dividend. To compensate for this the 
time he was a B.A. did not count in the seven years which 
was the tenure of a Fellowship. 

The Bachelors of Arts, whether Fellows or not, dined 
together at a separate table called the “Bachelors’ Table”. 
This was managed by the Senior Bachelor, who was the 
Bachelor of highest seniority, a Bachelor Fellow being 
regarded as senior to all Bachelors who were not Fellows. 
The office involved a good deal of work, for the Senior 
Bachelor had each evening, with tlie assistance of the Head 
Waiter, to order the dinner for the next day. It involved 
also some financial responsibility, for he was responsible 
for the payment to the College kitchens of the expenses of 
the dinners ; he was credited with a fixed sum for each 
dinner eaten by a Bachelor ; but if the kitchen bill at the 
end of the term exceeded that allowance, he had to pay the 
difference. As I had got my Fellowship very early, I was 
Senior Bachelor for nearly two years, and on the whole 
found the work agreeable. It was difficult, however, for 
the Senior Bachelor to dine out as frequently as he might 
wish to do, for if he were absent the dinner was ordered by 
the Bachelor next in seniority, and as he had no financial 
responsibility he often ordered the things he liked best with 
litde regard to their cost. One night’s absence might 
require economies for several days to get tliis account 
straight. Though the Bachelors’ Table still exists, the 
arrangements are quite different, and a Fellow dines at the 
High Table as soon as he is elected. 

Soon after taking my degree, I lectured for three hours 
on three mornings of rihe week at Cavendish College, a 

CAAIBRDDGE, 1879-1884 

college which had been founded to provide a place of 
residence for undergraduates younger than those usually 
admitted to the older Colleges. It was thought that per- 
haps one of the reasons why so few undergraduates went 
into business was because business men thought a start 
should be made earher than the usual age for leaving 
Cambridge. The College, however, was not a success, 
and after a few years was given up. It is now under the 
name of Homerton College, a College for the training of 
women teachers. 

I also took some private pupils ; among the first was 
Austen Chamberlain, now Sir Austen Chamberlain, K.G., 
who came because, under the regulations then in force, 
no one could take a Tripos in any subject unless he passed 
a preliminary examination in mathematics. I remember 
his father coming to Cambridge about this time and asking 
how his son was getting on. When he was told that he 
was doing very well and was certain to pass, he said he was 
not surprised, for he had never had but one fault to find 
with Austen, and that was he was such an awful Radical. 
Another of my pupils at this time was Eldon Gorst, who 
subsequently became High Commissioner for Egypt ; he 
was a candidate for the Mathematical Tripos and took a 
First Class in it. His motto was “ Thorough When 
he came back at the beginning of the term in which his 
Tripos took place, he mumbled so that it was only with the 
greatest difficulty I could make out what he was saying. 
I asked what was the matter, and he said that all his Hfe 
he had suffered from toothache and was determined that 
he would not be hampered by it in the Tripos, and so had 
had every tooth in his head taken out ; as his gums were 
not yet healed, the plate could not be put in, and so he 
could not articulate properly. 



I think it helps any teacher to have had some experience 
of teaching pupils one by one ; he realises what are the 
difficulties they meet with much more vividly than if he 
lectures to a class and only comes into contact with them 
through the written answers they send in to questions set 
in the lecture. I learnt, too, from my experience with 
these pupils, how greatly in most cases the concrete exceeds 
the abstract in the power of stimulating the mind and 
facihtating thought and work. One of my pupils came 
at the beginning of his third year with a very bad record. 
He was said to be idle, to take no interest in his work, 
and to have very little chance of getting through the Tripos. 
At first I agreed with this estimate, but we plodded on until 
we came to the subject of coUisions between clastic spheres. 
I knew he was fond of billiards, and so I pointed out to him 
that the rules he used for playing certain shots at bilhards 
followed at once from the mathematics. The result was 
marvellous. He had never before conceived that there was 
anything in mathematics that could interest any reasonable 
being. He now respected it, and began to work like a 
nigger : he was quite intelHgent, and in the few months that 
were left before the Tripos he learnt enough to take quite 
a respectable place among the Senior Optimes. If it had 
not been for the billiards he would have been ploughed. 

I was elected to an Assistant Lectureship m mathematics 
at Trinity College about two years after taking my degree. 
At this time the College were taking steps to remove the 
anomaly — to call it by no harsher name — that while all 
the candidates for the Mathematical Tripos paid fees to 
the College for lectures in mathematics, whether they 
attended them or not, they did all they could to avoid 
going to these lectures, and relied on private tuition for 
thek teaching. The system proposed by the College was 


CAMBRIDGE, 1879-1884 

that the College Lecturers, in addition to giving lectures, 
should take men individually, help them with their diffi- 
culties and advise them as to their reading. I was elected 
on the understanding that I should take part in this work. 
It was optional for those who were already Lecturers. 
The result was that I had most of the Trinity men coming 
to me, and as I kept on with some men from other Colleges 
who were already reading with me, I had about eighteen 
hours a week of mathematical teaching. I was only at this 
work for about two years. In one Tripos I had taught five 
out of the first six men in the hst. After saying this, I ought 
to acknowledge that in one Tripos, the very last man, the 
wooden spoon, was a pupil of mine.^ I think, however, 
that this was the greatest teaching triumph I ever had, for 
he was quite unable to follow any kind of mathematical 
reasoning. He could, however, learn pieces of book 
work ojf by heart, but without understanding them. I 
made him write out over and over again every piece of 
book work that was at all likely to be set in the elementary 
part of the Tripos until he could do them without mistake. 
This, however, did not make him safe, for there was no 
certainty that he could write out the right piece of book 
work in answer to a particular question, if the wording of 
the question differed to an appreciable extent from that 
to which he was accustomed. The issue became almost 
one of probabihty : if you have a number of balls, each 
with different numbers, and throw them at random into 
an equal number of holes, each hole having a number 

^ The “ Wooden Spoon ” was, as long as the Tripos list was arranged 
in order of merit, the man at the bottom of the list. He was so cdlcd 
because it was the practice for some of the members of his College to go to 
the Senate House, where he received his degree from the Vice-Chancellor, 
and immediately after he had done so to present him with a wooden spoon, 
or sometimes a wooden shovel emblazoned with the arms of his College 
and adorned with ribbons of the College colours. 




corresponding to that on one of the balls, what is the 
chance that the number of balls which go into the 
right holes is not less than the number of questions you 
have to answer correcdy to get through the examination ? 
Fortunately he had good luck and so obtained an Honours 
degree in mathematics in Cambridge University. 

Though eighteen hours a week spent in teaching may 
be thought to leave little time for research, I am strongly 
of opinion that in general some teaching should be com- 
bined with research, and that the teacher should not regard 
his teaching as neghgible in importance compared with 
his research. There is no better way of getting a good 
grasp of your subject, or one more likely to start more 
ideas for research, than teaching it or lecturing about it, 
especially if your hearers know very little about it, and it 
is all to the good if they are rather stupid. You have then 
to keep looking at your subject from different angles until 
you find the one which gives the simplest outhnc, and 
this may give you new views about it and lead to further 
investigations- I believe, too, that new ideas come 
more freely if the mind does not dwell too long on 
one subject without interruption, but when the thread 
of one’s thoughts is broken from time to time. It is, 
I think, a general experience that new ideas about a 
subject generally come when one is not thinking about it 
at the time, though one must have thought about it a good 
deal before. It is remarkable that when ideas come in 
this way they carry conviction with them, and depose 
without a struggle ideas which previously had seemed not 
unsatisfactory. The psychology of the incidence of ideas 
must be a very interesting subject. 

About the time I took my degree there were several 


burning questions before the University which led to a 
great many heated and in some cases bitter discussions. 
The first of these was compulsory Greek. At that time 
and until many years afterwards no one could take a 
degree unless he had passed an examination in Greek. 
This regulation was not an old one, for until 1822 Greek 
was not obhgatory. By 1880 the number of under- 
graduates who had done no Greek before coming to the 
University had increased so greatly that the regulation 
had become very irksome, and did not result in these 
students acquiring any appreciable knowledge of either the 
language or the literature of Greece. They crammed it 
up for a few months before the examination from transla- 
tions of the set books, which followed as nearly as possible 
the order of the words in the Greek text, and which had 
no literary value. This modicum of Greek was forgotten 
in less time than it had been learned. A Grace was sub- 
mitted to the Senate in November 1880, proposing that 
Greek be no longer compulsory, but was rejected by 180 
votes against 140. In January 1919 a similar Grace was 
proposed and passed without any opposition. 

A subject which excited even more interest, and which 
the undergraduates seized upon as an opportunity for 
indulging in very elaborate “ rags ”, was the proposal to 
admit students from Newnham and Girton to University 
Examinations, that they should have the right to sit for 
the various Honours Examinations, and the place they 
took in the examination should be published in the Hst 
issued by the Examiners. This would not, however, 
entitle them to a degree. As a matter of fact there had 
already been cases in which, by the courtesy of the Ex- 
aminers, women had been allowed to take the papers and 
these had been marked. Then place in the Tripos was not 



published in the University list, but it was not kept secret. 
In my year Miss Scott, who afterwards became Professor 
of Mathematics in Bryn Mawr University, U.S.A., was 
examined in this way in the Mathematical Tripos and took 
a high place among the Wranglers. The place she had 
taken had leaked out, and when the official list, in which 
of course her name did not occur, was read out in the 
Senate House, there was such an outburst of cheering 
when that place was reached, that it drowned the name of 
the man in the official list. He was in the Senate House, 
and as name after name was read out and his did not 
appear, he was in despair, and thought he must have made 
a dreadful mess of the examination. 

There was a long and very animated discussion on the 
proposal in the Senate House, and for some days before 
the voting fly-leaves for and against the proposal were as 
thick as leaves in autumn. There was vigorous whipping- 
up on both sides and the non-residents came up m large 
numbers. The undergraduates took it up with great 
gusto : they paraded the streets, carrying banners in- 
scribed with various sentiments, all, or nearly all, against 
the proposal. Figures supposed to represent women 
undergraduates in cap and gown were suspended across 
the streets. The proposal to allow women to take the 
Tripos papers and have their names published in the official 
list was carried by 398 to 366. \The activities of the under- 
graduates lasted long after the declaration of the voting, 
for on the night of the voting I went with a friend after 
dining in Hall to smoke in Dr. Jackson’s rooms, which 
were next to those of Mr Aldis Wright, the Vice-Master. 
We found a large goat trying to get past the Vice-Master, 
and forcing its way into his rooms. He had seized the 
goat by its horns, and the goat put down its head and 


butted, and the Vice-Master pushed. It was one of the 
most comical scenes I ever saw, for the Vice-Master was a 
very dignified old man, careful about his dress and with 
very stately manners. He was, too, in cap and gown, and 
his contest with the goat was about as incongruous as the 
Archbishop of Canterbury in full canonicals trying to drive 
an unwilling pig along a road. We went to his assistance, 
but he was evidently annoyed at being found in such a 
position and said he could manage by himself. All we 
could do was to tell a College porter to go and capture 
the goat, hoping that the Vice-Master would regard the 
removal of stray animals from the College as part of 
the porter’s duties, and accept his assistance. Some of the 
raggers had smuggled a goat into College, driven it up the 
Vice-Master’s staircase and then decamped.^ 

The victory for the women was due to the admirable 
way in which Newnham and Girton had been managed, 
and to the popularity of their principals. Miss Clough and 
Miss Bernard (afterwards Mrs Latham). When Newn- 
ham opened in 1871 in a small house in Panton Street, the 
earlier students were the pioneers of University education 
for women, and they had among them, as all pioneering 
bodies have, some who went their own way without 
troubling much about what people said about them. 
They dressed in the way that seemed to them best and did 
not follow the fashions. This made them conspicuous, 
exposed them to a good deal of ridicule, and hampered the 
progress of the movement for University education for 
women. To alter this without giving offence must have 
been a very delicate business, but Miss Clough was not 
only very charming and capable but also very tactful. 
She is reported to have said to a student who looked as if 
she never brushed her hair, “ My dear, you have very 



pretty hair, but I should like to see if it would not look still 
prettier if you did it in a way I will show you What- 
ever may have been the way she did it, she gradually 
reduced these eccentricities of dress until, at any rate to 
male eyes, they almost vanished. The popularity of Miss 
Clough and Miss Bernard induced some members of the 
Senate who did not believe in co-education in the abstract 
to say, if these ladies can turn out pupils like themselves 
it wiU be a very good thing, and we will give them a 
chance of doing it. No further steps were taken with 
regard to the position of women in the University until 
about the middle of the nineties, when a Syndicate was 
appointed to consider this question. They reported in 
favour of granting the titular degree of B.A. to those 
women who had fulfilled certain conditions of residence, 
had passed the examination such as the Little-Go which 
men have to pass before they can take a Tripos, and had 
obtained honours in some Tripos. The titular degree 
entitled the holder to put B.A. after her name, but did 
not carry with it the other rights and privileges which the 
B.A. degree gave to men. The argument put forward 
in favour of it was that, as is no doubt true, the general 
public who have not taken a degree themselves attach 
much more importance to B.A. after a person’s name than 
those who have. Head mistresses of schools therefore 
prefer a belettered staff, so that students of Newnham and 
Girton, since they could not put B.A. after their names, 
were at a disadvantage in obtaining appointments. Even 
if they had not to seek for employment it was a pardonable 
vanity which made them wish for some simple way of 
showing that they had passed a Tripos. The proposal, 
however, met with the most determined opposition. The 
debate on it in the Senate House lasted for three days, 



and the report of the speeches occupied sixty-six pages of 
the Reporter, There was an avalanche of fly-sheets. The 
editor of theCambridge Review took a postcard vote among 
undergraduates and resident B.A.s as to whether women 
should be admitted to the University (this, however, was 
not proposed by the Syndicate) and he sent out 2803 
postcards and got 2169 replies, of which 466 were favour- 
able and 1723 hostile. On the day of the voting there 
was a great influx of non-residents and the proposal was 
thrown out by the crushing majority of 1707 to 661. I 
beheve the number of voters has never been equalled. 
The undergraduates thoroughly enjoyed the fight : they 
could not vote, but everything they could do to defeat 
the proposal they did, and celebrated the result with a 
stupendous “ rag There is still (1936) in the windows 
of a well-known shop in the Market Place a photograph 
inscribed “ The historic rag of 1897 

No further steps were taken on this question until 1920, 
when a Syndicate of twelve members was appointed to 
report upon it. The members had been chosen with such 
care to give each side an equal representation that they had 
to issue two reports, A and B, each with six signatures. 
Report A was in favour of admitting women to the Uni- 
versity on the same terms as men ; they were to have the 
same degree (not a titular one but one carrying all the 
rights and privileges possessed by men). Report B was 
against this and thought the solution was to create a uni- 
versity or universities confined to women, like Bryn-Mawr, 
Smith, Vassar and Wellesley in America, which had been 
remarkably successful. Both these schemes, like the earlier 
ones, aroused fierce opposition. There were again long 
debates in the Senate House and sheaves of fly-sheets. The 
question was discussed by the undergraduates at a debate 



in the Union on the motion “ Tliis House does not consider 
that the granting of titular degrees without membership 
of the University meets the legitimate aspiration of women 
students This motion was lost, 185 voting for it and 
375 against. There was again a very large vote in the 
Senate House and the proposal to admit women to member- 
ship of the University was rejected, 712 voting for it and 
904 against. The behaviour of some of the undergraduates 
after the poll was declared in the Senate House was excep- 
tionally deplorable and disgraceful. A large band of them 
left the Senate House, proceeded to Newnham and 
damaged the bronze gates which had been put up as a 
memorial to Miss Clough, the first Principal. There were 
rumours that this was at the instigation of an M.A. who, 
when the poll was declared, shouted from the steps of the 
Senate House, Now go and tell Newnham and Girton 
This outrage aroused great indignation in the University 
among the undergraduates as well as the older members. 
The undergraduates at every College organised meetings, 
and at each of these a resolution was passed condemning 
“ such contemptible behaviour and in particular that of a 
small number of undergraduates which culminated in dis- 
graceful episodes and wanton damage’'. The authorities 
at Newnham dealt with this matter in a very dignified and 
charitable way. 

These rags are nearly always very stupid and not in- 
frequently lead to regrettable incidents The psycho- 
logy of a rag is that of a crowd, and this is not very different 
from that of a lunatic asylum. Some of the raggers really 
suffer from mild, temporary insanity. It is surprising 
how much some of them are affected by excitement alone 
without any aid from wine. I once at a bump supper, or 
something of that kind, sat next an undergraduate who was 



a bigoted teetotaller and to my knowledge drank nothing 
but ginger beer, and yet before the proceedings ended he 
was behaving as if he were very drunk indeed. It is the 
talking and shouting which brings this about, and a crowd 
can actually get intoxicated with the exuberance of its own 
verbosity alone. 

With regard to the women’s question. There was a 
widespread feeling among those who had voted against the 
proposal that somethmg should be done to remedy the dis- 
ability from which the women suffered in not having a 
symbol to indicate that they had taken a degree. Some, 
too, were influenced by the fact that there was a Royal 
Commission sitting on the University, and it was possible 
that if the University did not settle the question for itself 
the Commission would do it for them. 

A petition with many signatures was sent to the Council 
of the University asking them to take steps to settle the 
matter. The Council, after much consideration, issued 
proposals of their own which granted a titular degree to 
women, and allowed them to be members of Syndicates 
and Boards and to hold educational posts in the University 
such as Professorships or Lectureships. The grant of a 
titular degree had been rejected by a great majority in 1897, 
but this time it was accompanied by the vitally important 
condition that the number of women students at Newnham 
and Girton should not, except for a few oddments, be in- 
creased beyond five hundred without a special Grace of the 
Senate. This means that unless the University itself deter- 
mines otherwise, the proportion of women to men will 
be roughly one to ten, unless there is a considerable change 
in the number of male undergraduates. 

In the debate in the Senate House the scheme was 
criticised by the extremists on both sides, but they did not 



carry their opposition to the length of voting against it, 
and when it was brought before the Senate it was carried 
nemine contradicente. The scheme has now been in opera- 
tion for fourteen years and on the whole has worked well. 
Women have been appointed as Examiners in various 
University examinations ; they have been appointed Lec- 
turers in several faculties, and I have never heard anything 
but praise of the way they have done their work. Though 
the wave of feminism has almost died away, I do not think 
there is any desire on the part of those who do not believe 
in co-education to break away from the compromise of 
1921. One curious anomaly is that though women have 
no vote in the domestic ajflfairs of the University, they can 
vote in the election for representatives of the University in 

Until the early eighties. College Fellowships had to be 
vacated on marriage if the Fellow were not a Professor in 
the University, or Registrary, Librarian or Public Orator. 
In 1882 the Colleges altered this and made marriage no 
longer a bar to holding a Fellowship. This had a profound 
effect on social life in Cambridge. Until then the only 
University families resident in Cambridge were those of 
the Heads of Houses, Professors, the Registrary and a 
few clergymen, doctors or lawyers who happened to be 
members of the University. I doubt if there were more 
than sixty such families all told. It was then a very small 
society and it was distinctly an elderly one, as the great 
majority had married late in life, so that it contained very 
few young men or women. My wife, who was bom in 
Cambridge, and who has lived there all her Hfe, says that 
there were certainly not more than ten young women 
among them in her girlhood. As soon, however, as the bar 
against marriage was removed there was a stampede to 



matrimony. Many of the younger Fellows were already 
engaged, and were only waiting to get some appointment 
away from Cambridge to get married. When they could 
get married without losing their Fellowships and College 
appointments they did so, and there was a great influx of 
young brides into Cambridge. This not only greatly 
increased the number of University famflies resident in 
Cambridge, but changed the society from one which was 
decidedly elderly to one exceptionally youthful. The chief 
form of entertainment before the change had been elaborate 
and rather formal dinner parties ; with the coming of the 
brides hghter forms of entertainment came into vogue, 
dances, lunches, teas, river picnics and so on. 

The great increase in the number of Professors, Readers 
and Lecturers which has occurred since the war has also 
gready increased the number of University residents. In 
1882 there were 27 Professors, 2 Readers, 7 Demonstrators 
and 5 Teachers. In 1934 there were 72 Professors, 29 
Readers, 229 University Lecturers and 35 Demonstrators. 
In addition, many more laboratories requiring superinten- 
dents, museums requiring curators, and libraries requiring 
librarians, have been founded. I think that the number of 
heads of families engaged in University work must have 
increased tenfold since 1882, and from being a very small 
society it has grown into a very large one. 

Researches y 1880—84 

After my election to a Fellowship, I began some mathe- 
matical investigations on moving charges of electricity. 
I was attracted to this by the beautiful experiments on 
cathode rays which had lately been made by Crookes, and 



I was anxious to see what the behaviour of moving particles 
ought to be on Maxwell’s theory that magnetic forces could 
be produced not only by electric currents through wires, 
but also by changes in electric force in a dielectric. Charges 
of electricity did not figure at all prominently in this 
theory, and when Maxvv^ell in discussing electrolysis had 
for convenience of description to speak of a molecule of 
electricity, he says the phrase is out of harmony with the 
rest of his treatise. Helmholtz, who was a supporter of 
the theory, said he should be puzzled to explain what an 
electric charge was on Maxwell’s theory beyond being 
the recipient of a symbol. 

Since the electric force near an electrified particle varies 
very rapidly as the particle moves about, the behaviour of 
a moving charged particle would seem to afford a satis- 
factory method of testing the theory. I worked out, 
therefore, what on this theory would be the magnetic 
force produced by the moving particle, and what would 
be the mechanical force on the particle if it were acted upon 
by an external magnetic field. The results were published 
in the Philosophical Magazine for April i88i. I shall have 
to refer to them again when I am reviewing the progress 
of physics later on. The calculations in the paper were 
long, but there is one result which can be obtained 
without calculation which has formed the basis of a 
great deal of my work. The magnetic force is on 
Maxwell’s theory proportional to the rate of change in 
the electric force. If e is the charge and v the velocity, 
the electric force at a given point will be proportional 
to e, and its rate of change to ev ; hence at any point 
there will be a magnetic force proportional to ev ; but 
where there is magnetic force there is energy, and the 
amount of the energy per unit volume is proportional to 

RESEARCHES, 1880-1884 

the square of the magnetic force. Hence the energy in 
the space round the moving charge will be equal to a 
quantity where A is a positive quantity depending 

on the shape and size of the charged body. If the particle 
were not charged its energy would be m being the 

mass of the particle. Hence the total kinetic energy of 

the charged body is (^ + Ae'^v^, that is, its kinetic energy 

and therefore its behaviour under forces is the same as if 
its mass were not m but m-f-zAe^, Hence the mass has 
been increased by the charge, and since the increase is due 
to magnetic force in the space around the charge, the in- 
creased mass is in this space and not in the charged particle. 
It is interesting to compare this result with that for a sphere 
moving through water. When the sphere moves it sets 
the water around it in motion. The necessity of doing this 
makes the sphere behave as if its mass were increased by a 
mass equal to half the mass of a sphere of water of the same 
volume as the sphere itself. This additional mass is not in 
the sphere but in the space around it. Now no one supposes 
that the dynamics of the sphere moving through water is 
not Newtonian dynamics, and there is no reason to suppose 
that the Newtonian dynamics can not apply to the motion 
of the charged particle ; it is not the dynamics which 
need be altered, it is the place where the mass must be 
located. We must suppose that the place where the mass 
must be found is in the space surrounding the charged 
particle, and not in the particle itself. If we adopt the 
electrical theory of the constitution of matter we may 
suppose that all mass is electrical in its origin, and therefore 
not in the atoms or molecules themselves but in the space 
around their charges. The hydrodynamical analogue of 
this would be the case of the motion through water of 



exceedingly thin spherical shells, so thin that their mass was 
infinitesimal in comparison with that of the water they 
displaced. A collection of these would have a finite mass 
equal to half that of the water they displaced. 

The subject for the Adams Prize for 1882, a prize estab- 
Hshed to commemorate the discovery of Neptune by Pro- 
fessor Adams, was announced about the time I had finished 
the paper on the moving particle. It was an investigation 
on “ the action of two vortex rings on each other”. I was 
greatly interested in vortex motion since Sir William 
Thomson had suggested that matter might be made up of 
vortex rings in a perfect fluid, a theory more fundamental 
and definite than any that had been advanced before. 
There was a spartan simplicity about it. The material of 
the universe was an incompressible perfect fluid and all the 
properties of matter were due to the motion of this fluid. 
The equations which determined this motion were known 
from the laws of hydrodynamics, so that if the theory were 
true the solution of the problem of the universe would be 
reduced to the solution of certain differential equations, 
and would be entirely a matter of developing mathematical 
methods powerful enough to deal with what would no 
doubt be very complex distributions of vortex motion in 
the fluid. It seemed well worth trying if there were any 
cases we could solve, and finding whether these involved 
anything inconsistent with the properties of matter. 
Another thing that appealed to me was the analogy be- 
tween the properties of vortex filaments and those of 
the lines of electric force introduced by Faraday to repre- 
sent the electric field. Faraday's lines, like vortex fila- 
ments, could not be created nor destroyed, and they must 
also end on electric charges ; a vortex filament must end 
on the boundary of a fluid and we might conceive the 


RESEARCHES, 1880-1884 

electric charge acting as a boundary. In fact it seemed 
that even if the vorticity did not suffice to represent matter, 
it might yet give a very useful representation of the electric 
field. The investigation of the problem set for the Adams 
Prize, like most problems in vortex motion, involved long 
and complicated mathematical analysis and took a long 
time. It yielded, however, some interesting results and 
ideas which I afterwards found, valuable in connection with 
the theory of the structure of the atom, and also of that of 
the electric field. The essay was awarded the prize and 
was pubhshed in 1883 by Macmillan under the title A 
Treatise on the Motion of Vortex Rings. In the same year 
I gave, in a paper pubHshed in the Proceedings of the 
London Mathematical Society, the solution of the problem 
of finding the electrical oscillations which can occur on the 
surface of a conducting sphere. 

I began to work in the Cavendish Laboratory im- 
mediately after taking my degree. I had not done so 
before, though I used to go to the laboratory now and then 
to see Poynting or Schuster, who were working there. I 
was not fortunate enough to meet Maxwell on any of these 
occasions : he was then editing the unpublished papers of 
Henry Cavendish, and not engaged on any regular research. 
Maxwell’s view of the function of the laboratory was that 
it should be a place to which men who had taken the 
Mathematical Tripos could come, and, after a short train- 
ing in making accurate measurements, begin a piece of 
original research. Most of the men who were working 
there when I first knew it were of this type. There was 
no organised teaching of imdergraduates, though some 
lectures for candidates for the Natural Science Tripos and 
for medical students were given by the Demonstrator, 
WiUiam Garnett, afterwards Educational Adviser to the 



London County Council. He had been a candidate in 
the Mathematical Tripos when Maxwell was an Ex- 
aminer, and had so impressed him by the soundness of his 
work on the physical questions that he made him his 
Demonstrator. No fees were charged for working in the 
laboratory. Maxwell’s own lectures in the laboratory 
were not well attended. Indeed, in the last year the class 
consisted of an American and the eminent physicist who 
is now Sir Ambrose Fleming. I never heard Maxwell 
lecture in the laboratory, but I heard him in 1879 give 
the Rede Lecture in the Senate House on the Telephone. 
It was in the very early days of the telephone. The work- 
ing of the telephone was demonstrated by an experiment 
in which a tune was played in the Geological Museum and 
heard in the Senate House : the distance between the 
buildings was less than twenty yards. It was a very 
pleasant lecture to listen to : there were many instances 
of that “ pawky ” humour which flashes out so often in his 
verses. The Vice-Chancellor was not very happy in pro- 
posing the vote of thanks. He said they were much in- 
debted to Professor Maxwell, for he had helped them when 
they were in a great difficulty. They had asked everyone 
they could think of to be Rede Lecturer and they had all 
refused, and he did not know what would have happened 
if someone at the last moment had not suggested Professor 

Maxwell died in 1879 and was succeeded by Lord 
Rayleigh, who began work in the Lent Term of 1880. 
The work of the laboratory was much extended ; a scheme 
for instruction to undergraduates both in theoretical and 
practical work was organised. Glazebrook and Shaw were 
appointed Demonstrators, and to meet the cost of the 
apparatus required for these developments. Lord Rayleigh 


RESEARCHES, 1880-1884 

raised a sum of ^((^1500. All the new developments pros- 
pered, and the number of undergraduates studying in the 
laboratory increased rapidly. 

I began to work in the laboratory, in 1880, by 
attempting to detect the existence of some effects which 
I thought would follow from Maxwell’s theory that 
changes in electric forces in a dielectric produced magnetic 
forces. The results I obtained were not sufSciently definite 
to allow any positive conclusions to be drawn from them, 
and I then took up a research suggested by Lord Rayleigh. 
It was on some effects produced in the working of induc- 
tion coils by the electrostatic capacity of the primary and 
secondary of the induction coil. An account of the research 
was pubhshed in the Philosophical Magazine for July 1881. 
I then, again at the instance of Lord Rayleigh, began a much 
more difficult and lengthy research on the determination 
of the ratio of the electrostatic to the electromagnetic units 
of electric charge which ought, on Maxwell’s theory, to 
be equal to the velocity of light ; the work of previous 
observers showed that the difference was not great. About 
this time I was a candidate for the Chair of Apphed Mathe- 
matics which had just been estabHshed at Owens College, 
but was not successful. This was not surprising as the 
successful candidate was Arthur Schuster, who, like myself, 
had been a student at the College, was already teaching 
there and doing it very successfully. In 1883 I was elected 
a University Lecturer and in that capacity lectured on 
electrostatics and electromagnetism in the academic year 
1883-84. I also in the same year gave two courses of 
lectures at Trinity College, one on rigid dynamics and the 
other on statics and attractions, which were open to all 
members of the University. In the spring of 1884 I was 
elected a Fellow of the Royal Society. In the summer of 

97 H 


1884 Lord Rayleigh, who had stipulated when he accepted 
the Cavendish Professorship in 1879 that he must not be 
expected to hold it for more than five years, resigned the 
Professorship, and in December 1884 I was, to my great 
surprise and I think to that of everyone else, chosen as his 
successor. I remember hearing at the time that a well- 
known College tutor had expressed the opinion that things 
had come to a pretty pass in the University when mere 
boys were made Professors. I had sent in my name as a 
candidate without dreaming that I should be elected, and 
without serious consideration of the work and respon- 
sibility involved. When after my election I went into 
these, I was dismayed. I felt like a fisherman who 
with light tackle had casually cast a line in an unlikely 
spot and hooked a fish much too heavy for him to 
land. I felt the difficulty of following a man of Lord 
Rayleigh’s eminence. I remembered that I had never 
given lectures at which experiments had to be performed, 
and that I had never taught any classes in practical physics. 
Happily my want of experience in this respect was made 
less harmful than it would otherwise have been by the 
kindness of Glazebrook and Shaw, who continued to take 
charge of the classes in practical physics which had been 
organised by them when Lord Rayleigh was Professor. 



The Cavendish Laboratory 
and Professorship of Experimental Physics 

T he Cavendish Laboratory has played such a large 
part in my life that I hope to be pardoned if I say 
something about its history. Though many very 
great discoveries in physics had been made in Cambridge 
as far back as Nevrton's time, it was not until 1869 that 
steps were taken to have in the University a physical labora- 
tory and a Professor of Experimental Physics. Newton 
and Stokes had made their experiments in their own rooms 
with their own apparatus and at their own cost. In the 
early sixties, however, the importance of science in educa- 
tion was warmly advocated by Huxley, Roscoe and Lockyer 
along with others, and considerable interest in the teaching 
of science was aroused. In 1866 CHfton was appointed to 
a new Chair of Experimental Physics in Oxford and the 
building of the Clarendon Laboratory was commenced in 
1868 and finished in 1872. In Cambridge there was in 
addition to the general recognition of the importance of 
science in education a special one for making provision for 
the teaching of heat, light, electricity and magnetism, for 
in 1868 these subjects had been added to those included in 
the Mathematical Tripos, and it was necessary to provide 
for instruction in tliem. A Syndicate appointed in Novem- 
ber 1868 to consider how this might best be done, reported 
in February 1869 in favour of establishing a Professorship 
and Demonstratorship of Experimental Physics, and the 



erection of a physical laboratory adequately supplied with 
apparatus ; they thought this would cost ^[^62,00. The 
University was then so poor that it was clear that there 
would be great difficulty in raising this sum. The situation 
was saved, however, by the Chancellor of the University, 
the 7th Duke of Devonshire — ^who had been first Smith’s 
Prizeman and Second Wrangler— offering to provide funds 
for building the laboratory and stocking it with apparatus. 
The building alone cost ^1^8450, considerably more than 
the estimates, and the Duke not only defrayed this, but also 
continued to provide apparatus for the laboratory until 
Maxwell, three years after the laboratory had been opened, 
reported “ that it contained all the instruments required 
by the present state of science ”, It has never since been 
in this condition.^ If it had not been for the generosity 
of the Chancellor, though no doubt in time the University 
would have had a physical laboratory, it would not have 
had Maxwell as a Professor, and the Cavendish Laboratory 
would have been without the inspiration and tradition 
which it owes to its first Professor. In February 1871 the 
University sanctioned the creation of a Professorship in 
Experimental Physics, to which Maxwell was appointed in 
March of the same year. It was believed at the time that 
the University had first approached Sir William Thomson 
and then von Helmholtz, the great German physicist and 
physiologist, but neither of these could see his way to 
accept the post. At the time of his election Maxwell’s 
work was known to very few, and his reputation not com- 
parable with what it is now. The Treatise on Electricity 
and Magnetism did not appear until two years later, and 

^ The list of these mstruments was published in the Cambridge University 
Reporter (May 15, 1877). It is a striking instance of the difference between 
the apparatus which was then considered adequate, with what would be 
so now. 



though he had pubHshed the fundamental ideas long before 
in the scientific Journals, they had attracted but Htde atten- 
tion, and his reputation was based mainly on his work on 
the kinetic theory of gases. Indeed, even at the time of 
his death the truth of his supreme contribution to physics 
— the theory of the electromagnetic field — ^was an open 
question. It was only when nearly ten years later Hertz 
detected by experiment the electromagnetic waves, which 
were the characteristic and essential part of his theory, and 
which distinguished it from all others, that the importance 
of his work was adequately reahsed. Maxwell delivered 
his inaugural lecture in October 1871. It is a very able 
and interesting essay on the functions of experimental 
work in the laboratory in University education. It has 
been quoted very frequently, perhaps oftener than any 
other of his writings. But for the moment it was almost a 
fiasco. Sir Horace Lamb, who was at it, describes it in the 
James Clerk Maxwell Commemoration Volume : ‘‘ The 
announcement of it had been made in such a way that it 
had escaped the notice of the older members of the Univer- 
sity. It was not given in the Senate House, the usual place 
for such lectures, but in an obscure lecture-room. The 
result was that only about twenty were present, and these 
were all young mathematicians who had just taken, or were 
about to take, the mathematical Tripos, but more remains 
behind.” I quote Sk Horace Lamb’s account of this ; 
“ The sequel was rather amusing. When, a few days later, 
it had been announced with proper formality that Profes- 
sor Maxwell would begin his lectures on heat at a certain 
time and place, the dii majores of the University, thinking 
that this was his first public appearance, attended in full 
force out of compliment to the new Professor, and it was 
amusing to see the great mathematicians and philosophers 


of the place such as Adams, Cayley, Stokes, seated in the 
front row while Maxwell, with a perceptible twinkle in 
his eye, explained to them the difference between the 
Fahrenheit and Centigrade scales of temperature/' 

It was rumoured afterwards, and perhaps it is not 
incredible, that Maxwell was not altogether innocent in 
this matter, and that his personal modesty, together with a 
certain propensity to mischief, had suggested this way of 
avoiding a more formal introduction to his Cambridge 

During the erection of the laboratory he lectured each 
term in such rooms as happened to be vacant. He said 
he went about like a cuckoo, dropping ideas about heat 
in the chemical laboratory in the October Term, about 
electricity in the botanical laboratory in the Lent Term, 
and about magnetism in the New Museums in the Easter 
Term. His lectures were quite elementary and were not 
so well attended as they ought to have been. Some who 
attended have expressed the pleasure they got from the 
quips and cranks and dry pawky humour which now and 
then broke through the crust of science. This side of his 
character comes out very clearly in the verses which he 
wrote from time to time, and which are published at the 
end of Lewis Campbell’s biography. 

The laboratory was formally opened by the Chancellor 
of the University in October 1874. I believe W. M. 
Hicks, who was afterwards Professor and then Principal 
at Sheffield University, was the first to come, but others 
gradually drifted in, most, though not all, men who had 
lately taken the Mathematical Tripos and had no previous 
experience of experimental work. At first they were set 
to read scales and verniers, to measure times of vibrations, 
to use a reflecting galvanometer, to measure the resistance 

Photo ■ I'urncr & Sons, Ctinihrid^e 


The building on the extreme left is the new extension. 


of a wire ; after a short time spent in this way, they were 
often set to measure the horizontal component of the 
earth’s magnetic force by a magnetometer of the Kew 
pattern. Maxwell had a high opinion of the training to 
be got by using this instrument. It afforded practice not 
only in reading scales and measuring times but also in 
making adjustments, and the accuracy with which these 
had been done was indicated by the value obtained for the 
magnetic force. After a short course of this kind they 
began to work at a specific problem. He liked the student 
to have thought of one for himself. “ I never,” he said, 
“ try to dissuade a man from trying an experiment. If 
he does not find out what he is looking for he may find 
something else.” In most cases, however, the student 
wished Maxwell to select a subject for him. Maxwell 
did so, and spent great pains in planning how the experi- 
ment had best be tried. When he was satisfied with this, 
he acted on what I believe to be the right principle of 
encouraging the student to try to overcome the difficulties 
himself, and that it is better for the teacher to do this 
rather than to remove them out of his way. Maxwell 
went round the laboratory for an hour or two most days, 
generally accompanied by his dog, and talked with the 
students about their researches. They also got valuable 
help fiom the Demonstrator, W. Garnett, who was a 
good amateur carpenter, and was always ready to help 
those who were not, in making the alterations in the 
apparatus or the simple contrivances which are continually 
being called for in experiments. This help was especially 
valuable, for at the beginning there was no skilled work- 
man in the laboratory. At first all the* students were 
research workers, nearly all of them graduates. The first 
undergraduate who worked in the laboratory was my 


old friend H. F. Newall, who later became Professor of 
Astro-Physics at Cambridge. He in his first term, 
against the advice of his tutor, entered this unexplored 
region, and like most explorers found the going was 
not easy. 

Important researches were made between 1874 and 
1879 in the laboratory by G. Chrystal, later Professor of 
Mathematics in Edinburgh University, on the accuracy of 
Ohm’s Law ; by Donald MacAlister, Senior Wrangler 
and later Sir Donald MacAlister, Principal of Glasgow 
University, on a new proof that the attraction of a point 
charge of electricity varies inversely as the square of 
the distance ; by R. T. Glazebrook (Sir R. T. Glaze- 
brook, K.C.B., F.R.S.), later Principal of Liverpool Uni- 
versity, after that Director of the National Physical 
Laboratory, on the wave surface in a biaxial crystal ; by 
Arthur Schuster, afterwards Sir Arthur Schuster, F.R.S., 
in spectroscopy ; by J. A. Fleming, now Sir Ambrose 
Fleming, on the measurement of resistances. Maxwell 
himself did not do any continuous experimental research 
in Cambridge. Though he came to Cambridge in 1871, 
the laboratory was not opened until 1874. Afterwards, 
the greater part of his time was spent in editing the works 
of Henry Cavendish, a pious duty for a Cavendish pro- 
fessor. Cavendish, though he only published two papers, 
left twenty packages of manuscripts on mathematical and 
experimental electricity. Maxwell copied these out with 
his own hand. He saturated his mind with the scientific 
literature of Cavendish’s period ; he repeated his experi- 
ments ; he was especially attracted by one where Caven- 
dish had been his own galvanometer and had estimated 
the strength of the current by the shock it gave him when 
he passed it through his body. Visitors to the laboratory 


had currents passed through them to see whether or not 
they were good galvanometers. The papers were pub- 
lished in 1879 under the title, The Electrical Researches 
of the Honourable Henry Cavendish. They showed that 
Cavendish was even a greater man than had been thought. 
He anticipated Faraday in the discovery of the property 
known now as Special Inductive Capacity and measured 
its values. He had formed the conception of electrostatic 
capacity, had anticipated Ohm’s Law, had made experi- 
ments which proved that the force exerted by a point charge 
of electricity varies inversely as the square of the distance 
from the point. These papers confirm the impression 
produced by those published in his lifetime, that he was 
a superb experimenter. He had the gift, Hke Lord 
Rayleigh, of seeing what was the vital point in the experi- 
ment, and though the apparatus as a whole might look 
untidy and haphazard, the parts that really mattered were 
all right It was a “ rum ’un to look at but a beggar to 
go ”. A striking feature in these papers of Cavendish is that 
they are quantitative; definite measurements are given 
of the various effects. A great deal of the work done by 
the earher experimenters had been, as was natural in the 
infancy of the science, qualitative. They tried to find 
whether an effect got greater or less under a certain 
change of conditions, but not how much greater or how 
much less. Cavendish, who measured everything he had 
to do with, measured electricity and speaks of inches of 
electricity. His researches on electricity were made before 
the death of his father. Lord Charles Cavendish, who was 
also interested in science, in 1783 . Until then he had hved 
with his father, and his apartments were a set of stables 
fitted up for his accommodation. After his father’s death 
he moved to a house in Clapham, the greater part of which 


was used for his experiments. It was here that he made 
his discovery of the composition of water, and measured 
by means of the torsion balance the density of the earth. 
There is no evidence that he made any more electrical 
experiments. It was natural that Cavendish in his earlier 
researches should have worked at electrical subjects, for 
at that time they were the ones which attracted far more 
attention than any others. The discovery of the Leyden 
jar, Franklin’s researches, particularly the invention of the 
lightning conductors, had aroused such an interest in 
electricity, and provided so many subjects for research, 
that they seemed the most promising, as they were 
the most popular, ways of obtaining new and important 

C Cavendish’s life was dominated by science to an extent 
which seems almost incredible. From the evidence of his 
contemporaries, given in Wilson’s biography, he never 
talked about anything else. In spite of his family tradi- 
tions, he never took any interest in public affairs. In the 
latter part of his life he was very wealthy, yet he never 
paid any attention to his financial matters. When his 
balance at the bank was 80,000, his banker thought he 
ought to go to him and advise him to invest some of it, 
instead of letting it lie idle, earning no interest. He went, 
and Cavendish was very angry and said, What do you 
come here for ? ” He told him. Cavendish said, If it 
is any trouble to you I will take it out of your hands, so 
do not come here to plague me. What do you want me 
to do ? ” “ Perhaps you would like to have ^,(^40,000 

invested.” “ Do so, and don’t come here to trouble me 
or I will remove it.” 

He never wasted any time in deciding what he should 
do in the private affairs of life ; he always did what he 


had done before. He took the same walk at the same time 
every day of his life, walking in the middle of the road 
to avoid meeting anybody he might chance to pass on the 
footpath. His tailor provided him on a fixed day in the 
year with a new suit which was a repHca of the old one. 
He was a misogynist as well as a recluse. His female 
servants were there on the understanding that they should 
keep out of his sight ; if he saw them they were dismissed. 
Even with his housekeeper his communications were 
written, not spoken. 

The occasions when he went into society were all 
within the ambit of the Royal Society, to which he had 
been elected in 1760. He attended regularly its meetings, 
the receptions given on Sunday evenings by its President, 
Sir Joseph Banks, and above aU the meetings of the Royal 
Society Club, a dining-club connected with the Royal 
Society which is still flourishing. It appears from the 
information contained in The Annals of the Royal Society 
Club by Sir Archibald Geikie, that at the meetings of this 
club, when he was surrounded by men of science, he was 
a very different person from what he was in ordinary hfe. 
There is in existence an account of a club dinner at which 
Cavendish was present, written by a French guest. After 
describing the dinner itself, when nothing but porter was 
drunk, and this out of cylindrical pewter pots, which 
are much preferred to glasses because one can swallow a 
whole pint at a draught ”, he goes on to speak of the 
number of toasts which were drunk after the cloth had 
been removed, and the wine was going round. After 
these had been drunk and followed by brandy and rum, 
he says, I repaired to the Society [the Club dinners began 
at 5, and the meeting of the Society at 8] along with 
Messrs Banks, Cavendish, Maskelyn, Auhert and Sir 



Henry Englefleld. We were all pretty much enlivened 
but our gaiety was decorous/’ 

Cavendish was made a member of the Club in 1760, 
a few months after he had been made a Fellow of the 
Royal Society, and in accordance with his habit of doing 
the same thing over and over again, he attended with a 
regularity which has never been even approached by 
anyone else. In tliose days the Club met every Thursday 
throughout the year, much more frequently than it does 

From 1770 onwards until the end of his life, his record 
was never lower than 44 attendances in the year, and was 
usually about 50. In 1784 January began on a Thursday 
and December ended on Friday, thus allowing 53 dinners 
in the year, and he was present at every one. He always 
put his hat on the same peg. 

He not only came himself, but also frequently brought 
guests. One year he had as many as nineteen. These 
were not all physicists or mathematicians ; some were 
doctors, some engineers, travellers, naval ofEcers. Pro- 
fessor Playfair, who was a guest at these dinners, says, “He 
never speaks at all but that it is exceedingly to the 
purpose, and either brings some excellent information or 
draws some important conclusion. His knowledge is very 
extensive and very accurate. Members of the Royal 
Society look up to him as one confessedly superior.” 

Dr. Wollaston, who also often dined at the Club, said, 
“ The way to talk to Cavendish is never to look at him but 
to talk as it were into vacancy, and then it is not unlikely 
you will set him going His silence in general society 
may have been because he had nothing to say about the 
things which interested his audience, I have known more 
than one man of science who would sit through a long 


dinner without saying a word to those sitting next to him, 
and yet would speak freely and well on things that in- 
terested him. 

In the case of Cavendish we must remember that the 
motto of the Royal Society is NulUus in verba, and his 
family motto Cavendo tutus, and neither of these encourages 

Maxwell’s health began to fail at the beginning of 1879 
and he was able to spend only very httle time in the labora- 
tory. He went to Glenlair, his house in Galloway, for the 
summer but rapidly grew worse. He was brought back 
to Cambridge to be under the care of his favourite physician. 
Sir George Paget. He suffered much pain, which he bore 
with great fortitude. He died on November 5, 1879. 

The Professorship had been established under the regu- 
lation that it was to “ terminate unless the University by 
the Grace of the Senate shall decide that the Professorship 
shall be continued ”. A Grace to continue the Professor- 
ship was passed on November 20, 1879. Lord Rayleigh 
was persuaded to become a candidate and was elected on 
December 12, 1879. He began his work at the laboratory 
in the Lent Term of 1880, giving a course of lectures on 
physical apparatus which were well attended. He also 
began to organise and develop the teaching of physics 
to undergraduates, which had hitherto been somewhat 
neglected. The need for this was pressing, for the num- 
ber of students taking physics was increasing quickly, and 
also because the University had decided that in 1881 the 
Natural Sciences Tripos was to be divided into two parts. 
In Part I candidates were expected to take the more elemen- 
tary parts of three or more subjects, while in Part II they 
were expected to specialise in one subj ect. This Part would 
demand a knowledge of the more advanced parts ofphysics, 



and for this there was as yet no provision. To provide 
it would require a good deal of extra apparatus, and one 
of the first things Lord Rayleigh did was to raise a sum 
of about 5(^1500 for this purpose by asking for donations 
from a number of his friends. Garnett resigned his 
Demonstratorsliip in the Lent Term of 1880, and R. T. 
Glazebrook and W. N. Shaw were appointed Demon- 
strators. They, in consultation with Lord Rayleigh, 
evolved a scheme for instruction in practical physics 
whichj in its essentials, was the same as that now in force 
more than fifty years later. There were demonstration classes 
each term on some branch of elementary physics ; these 
were three times a week, each lasting for two hours. The 
subjects included in Part I of the Natural Sciences Tripos 
were covered in three terms. A student was required to 
finish one experiment and write out in his notebook an 
account which satisfied the Demonstrator before he could 
proceed to another. A similar plan was adopted for the 
demonstrations in the advanced subjects. The students 
were not limited here, however, strictly to two hours, 
but could stay longer if they wished. There was a labora- 
tory notebook for each experiment^ and the students wrote 
the account of their work in this as well as in their own 
book. This plan worked well ; the student thought he 
was writing for posterity and took special pains with his 
description of his experiment. This was good practice 
in a very important thing — clear exposition of the results 
he had obtained. The numbers attending the elementary 
classes increased so rapidly that, before the end of Lord 
Rayleigh's tenure of the Professorship, they had to be 
duplicated, and two additional Demonstrators appointed 
to assist Glazebrook and Shaw. 

Almost as soon as he came to Cambridge, Lord Rayleigh 


began the determination of the absolute measure of various 
electrical quantities, which raised the standard of electrical 
measurement to a higher plane. He began with the 
re-determination of the ohm. There had been a deter- 
mination of this made in 1864 under the direction of a 
Committee of the British Association. The experiments 
were made by Maxwell at Eang’s College, London, where 
he was then Professor. They issued a standard, afterwards 
called the B.A. Ohm, which professed to have a resistance 
in absolute measure equal to 10’. Later experiments had 
led to serious doubts about the accuracy of this standard, 
the differences covering a range of about 3 per cent. The 
apparatus used by the Committee was in the Cavendish 
Laboratory, and was used by Rayleigh in collaboration 
with Mrs Sidgwick and Schuster. The apparatus was set 
up, and experiments commenced, in the summer of 1880 
and the experiments concluded by the end of 1881. The 
result was that the resistance in absolute measure of the 
B.A. unit was *987 x 10^ instead of 10® as it ought to have 
been. The greater part of the error was traced to a very 
commonplace cause, a mistake in arithmetic. In the experi- 
ments several instruments had to be observed simultane- 
ously, and visitors to the laboratory were sometimes called 
on to take a hand. I remember seeing Mr Arthur Balfour 
set down to read a galvanometer. 

Rayleigh did not stop here. He repeated the experi- 
ment, using the same method but larger apparatus, then 
he made another determination using a different method. 
The three determinations gave very concordant results. 
These experiments had taken three years of very difficult 
and often harassing work ; for example, at one stage the 
readings taken one day did not agree with those on the 
next, and it took two months to get over this difficulty. 



Lord Rayleigh, in collaboration with Mrs Sidgwick, went 
on to determine in absolute measure the other electrical 
standards : the ampere, the standard of electric currents, and 
the volt, the standard of electromotive forces. 

Lord Rayleigh, by the experiments he made when he 
was Cavendish Professor, raised the standard of electrical 
measurement to such a high level that it may be claimed 
that here he has changed chaos into order. His results 
have stood the test of time ; they have been confirmed by 
later measurements made with larger and more elaborate 
apparatus, and have been adopted by International Con- 
gresses as the basis for the" definition of the Ohm, Ampere 
and Volt for legal purposes. The accuracy of the value of 
the standards is of vital importance both to the physicist 
and to the electrical engineer. The physicist in his mathe- 
matical investigations must use the absolute measures of 
any electrical quantity which may occur in them, and 
express the results he obtains in terms of them. Suppose, 
for example, that his calculations indicate the existence of 
a certain effect whose magnitude depends on the electrical 
resistance of a piece of the apparatus he is using to detect 
it. If he wishes to test this in the laboratory, he has 
to measure this resistance in ohms. If the absolute 
measure of the ohm is wrong, the results he obtains 
will not be in accordance with those predicted by the 
theory ; he may conclude that his theory is wrong and 
must be abandoned, whereas the difference is due to the 
error in the ohm. When Lord Rayleigh began his experi- 
ments there was an uncertainty of about 3 per cent in the 
absolute value of the ohm. This might cause a discrep- 
ancy of this amount between the theoretical and observed 
results, far greater than could be accounted for by errors in 
carefully made experiments. Again, the electrical engineer. 


like the physicist, uses the absolute value of electrical 
quantities in his calculations, and if the ohm, ampere or 
volt are wrong, the actual efficiency of a dynamo or motor 
will be different from the estimate. This difference in a 
huge industry like electrical engineering, when expressed 
in terms of money, may involve very large sums. 

Besides his experimental works, Lord Rayleigh pub- 
hshed many theoretical papers of first-rate importance 
during his stay in Cambridge. It was his custom not to 
come to the laboratory in the morning if he was not 
lecturing, but work in his study at home. I think the one 
that gave him the greatest pleasure was that on the soaring 
of birds, in which he gave an explanation of the striking 
fact that some birds, e.g. gulls and albatrosses, can, without 
moving their wings, and in the absence of an upward wind, 
soar round and round at a constant height, and even in 
some cases get higher and higher. Rayleigh showed that 
this might be possible even where the wind was horizontal, 
if its velocity increased with the height above ground. 
The bird must go downwards when flying with the 
wind and upwards when flying against it. I remember 
his talking to me about this before it was pubhshed ; in 
fact he felt some hesitation about publishing it because 
he thought it was too pretty to be correct. It is now, I 
beUeve, universally accepted. 

There were several researches going on in the labora- 
tory besides those made by Lord Rayleigh himself. Glaze- 
brook determined the ohm by a method different from 
either of those used by Lord Rayleigh, and completed a 
research on the reflection of light from the surface of a 
uniaxial crystal. Shaw began his meteorological investiga- 
tion on the comparison of different forms of hygrometers. 
Sir George and Sir Horace Darwin endeavoured to find 


evidence of tides in the earth’s crust due to the motion of 
the moon, but the conditions were not sufEcicntly free from 
other disturbances to allow this effect to be detected. 

No mention of the Cavendish Laboratory at this period 
would be complete without mention of Mr George Gordon, 
who was in charge of the workshop. He had been a ship- 
wright in Liverpool and was very skilful and quick with the 
adze. His work was not pleasing to the eye but it did 
what it was expected to do, which was all that Lord Ray- 
leigh demanded. 

We have been fortunate enough to have had as 
teachers in practical work in physics at the Laboratory, 
in addition to those I have mentioned : W. C. Dampier 
Whetham, F.R.S. (now Sir William Dampier) ; Professor 
H.L, Callendar, F.R.S. , an intellectual Admirable Crichton, 
who took first classes in both the Classical and Mathematical 
Triposes and was awarded a Fellowship at Trinity College 
for Physics ; the Rev. T. C. Fitzpatrick, who later became 
President of Queens’ College, Cambridge ; S. Skinner 
(later President of the Southwestern Polytechnic, Chelsea) ; 
C. E. Ashford (later Head Master, Royal Naval College, 
Dartmouth, now Sir C. E. Ashford), and many others. 

Mr G. F. C. Searle, F.R.S., who first began to demon- 
strate in 1891, has done more than anyone else for the teach- 
ing of practical physics at Cambridge. It was only in the 
year 193 5 that, owing to the age limit, he gave it up after 
forty-four years’ uninterrupted service, teaching all thetime 
the largest class — that for students who are going in for 
Part I of the Natural Sciences Tripos. Nothing approaching 
such a long tenure as this of the office of Demonstrator 
has ever come to my knowledge. In general the zeal for 
demonstrating fades away after a few years : the work is 
hard and may be monotonous, but Searle is as keen now 



as he was forty-four years ago ; indeed it was only the 
other day (1935) that he invented a new and very beautiful 
experiment for his course. He has a real enthusiasm for 
the subject ; he is not content with merely teaching it. 
He has taken infinite pains and thought to improve the 
course, and replace old experiments by others which have a 
greater educational value. His experiments are never 
commonplace : they have always a freshness and elegance 
which makes one want to do them. After he has got the 
idea, he works away at the experiment untU he has found 
the form which gives the most accurate results, and so is 
suitable for training the students in accuracy of measure- 
ment. This often involves a great deal of work. He then 
writes out an account of the theory, followed by a descrip- 
tion of the way the experiment is made. He takes infinite 
pains to make his meaning clear, making one attempt after 
another until he is satisfied. He then makes a fair copy 
in his own hand, and this is placed in the laboratory for the 
use of his students. He must have made, I should think, 
many more than a hundred of these. Since for more 
than forty years practically every Cambridge man taking 
physics has been a pupil of Dr. Searle, the influence he 
has exerted on the teaching of practical work in physics 
must have been comparable with that exerted by Routh 
on the teaching of mathematics. 

A very important person in a physical laboratory is 
the man in charge of the workshop. The smooth running 
of the laboratory depends upon him almost more than 
upon anyone else, and to be successful he must have many 
qualifications. Besides being a good workman he must 
be a man of strong character, for he has to maintain 
discipline among the younger assistants. He has to be 
business-like, for the buying of stores and materials will be 



in his hands, and he requires the tact of a diplomat to 
reconcile the claims on the workshop of those engaged 
in teaching, and those working at research. One of my 
first duties on becoming Professor was to appoint such a 
man to superintend the workshops, for Gordon, who had 
held this post, left to be private assistant to Lord Rayleigh. 
I was fortunate in finding in a young Scotsman, Mr D. S. 
Sinclair, a man who combined all these qualities. Though 
a good mechanic, he knew nothing about glass-blowing 
when he came to the Laboratory. I sent him to have a 
few lessons, and after two or three months he became 
a very expert and exceptionally quick worker. He did 
very good work for the Laboratory for three years, when 
he left to take a good appointment in an engineering firm 
in India. He was succeeded by Mr A. T. Bartlett, who 
after five years’ service left to take up electrical engineering. 
He now holds an important position as head of the 
Research Department of the English General Electric 
Company, After him came Mr W. G. Pye, the son of 
Mr Pye who managed the workshop established by Mr 
Dew-Smith for making apparatus for use in the Physio- 
logical Laboratory, and which developed into the Cam- 
bridge Scientific Company. W. G. Pye rendered us very 
efficient service from 1892 to 1899, when he left to start 
in business in Cambridge as a scientific instrument maker. 
This busiaess was very successful. It spcciahsed in pro- 
ducing well-made and well-designed apparatus at a 
moderate price suitable for school laboratories or for 
elementary classes in the university. An offspring of this, 
Pye s Radio, which bears his name, is a still larger concern 
giving employment to many hundred workers. He was 
succeeded in 1899 by our present assistant, Mr F. Lincoln, 
who has rendered invaluable assistance in the work of the 


Laboratory for thirty-six years. Mr Lincoln came to the 
Laboratory in 1892 when he was a very small boy, so 
small that he had to stand on a box to reach the bench. 
W. H. Hayles, who afterwards became chief lecture 
assistant, was appointed by me in the first term of my 
Professorship. He rendered good service to the Laboratory 
for more than fifty years, when he retired imder the age 
Hmit. He was a skilful photographer, and very expert in 
making lantern slides. He had the valuable quality of 
reahsing to the full what an important part he played in 
the lecture j and spared neither time nor trouble to make 
the experiment succeed. 

My first course of lectures was given in the Lent Term 
of 1885, The beginning was not very auspicious, for in 
my first lecture, though I got on quite well until about 
ten minutes before the time to stop, I then became very 
dizzy : I could not see my audience, and thought I was 
about to faint and had to dismiss the class. I recovered 
in a few minutes and have never suffered in this way again. 
I attribute it to having turned round to look at the black- 
board at my back too often. I have sometimes felt this in 
a shght form when lecturing in a darkened room and 
showing many lantern sHdes, and often turning my eyes 
from the brightly lighted screen to the darkened room. 

Immediately after my election to the Professorship, I 
began, in collaboration with my old friend, Richard 
ThrelfaU, some experiments on the passage of electricity 
through gases. ThrelfaU had just taken a First Class in 
physics and chemistry in Part II of the Natural Sciences 
Tripos, but his enthusiasm for physics began long before 
he came to Cambridge. He had as a boy a laboratory 
and workshop at his home near Preston, and experimented 
during the vacations. When working at high explosives 


he had an explosion which blew off large parts of several 
fingers. In spite of this he was one of the best experi- 
menters I ever met, and very skilful in the use of tools. I 
am myself very clumsy with my fingers, so that his 
assistance was of vital importance. This was the first of 
my experiments on the passage of electricity through 
gases, and since then there has, I think, never been a time 
in which I have not had some experiments in hand on that 
subject. I was attracted to it because I wished to test the 
view that the passage of electricity through gases might 
be analogous to that through liquids, where the electricity 
is carried by charged particles called ions. My view was 
that whenever a gas conducts electricity, some of its 
molecules must have been split up by the electric forces 
acting on the gas, and that it is these which carry the 
electricity through the gas. On this view, a gas in which 
all the molecules are in the normal state cannot conduct 
electricity. My idea at that time was that some of the 
molecules were split up into two atoms, one of which 
was positively, the other negatively, electrified, and my 
first experiments were intended to test this idea. It was 
not until 1897 that I discovered that the decomposition 
of tbe molecule was of quite a different type from ordinary 
atomic dissociation ; then I found that one of the bodies 
into which the molecule split up, the one carrying the 
negative electricity, is something totally different from an 
atom, and that its mass is less than one-thousandth part of 
that of an atom of hydrogen, the lightest atom known. 

Towards the end of my first years of office, T. C. 
McConnel, Fellow of Clare College, a man with a 
singularly acute and original mind, and who had done 
valuable original work in optics whilst at the Laboratory, 
left Cambridge to take part in a large business in Man- 


Chester with which his family were connected. Un- 
fortunately his health broke down shortly afterwards and 
he spent the rest of his life in Switzerland, where he made 
valuable observations on the properties of ice. He ex- 
plained the bending of ice, m cases when regelation was 
impossible, by the shpping of one crystal over another. 
He was one of the first to realise the importance of shp, 
and the difference between the properties of a single 
crystal and an aggregate. 

Threlfall succeeded McConnel as Assistant Demon- 
strator, but was shortly afterwards appointed Professor of 
Physics in the University of Sydney, N.S.W. His first 
experiences were very characteristic ; as soon as he 
arrived in Sydney he drove to the University to see the 
laboratory, but when he arrived there he was told there 
was no laboratory. Then he said he was going back to 
England, as he was not going to be a Professor of Experi- 
mental Physics without a laboratory where he could make 
experiments. They took him over the building, and 
showed him a room here and another there which he 
might use for his laboratory, but he said this would not 
do ; he must have a proper laboratory. Then they 
promised to apply to the Government and use all their 
influence to get it to build a laboratory for the University. 
Then he agreed to stay, and broke to them that, as he 
knew he would not be able to get physical apparatus in 
Sydney, he had ordered in London apparatus which would 
cost about ^2000, and which would be coming over 
before long. For some months the Government did 
nothing towards providing a laboratory, but in the 
meantime Threlfall had become very friendly with the 
Prime Minister, who was very fond of working with a 
lathe, and got many useful tips from Threlfall, who was 



an adept at this work. In spite of ThrelfalFs attempts 
to induce the Prime Minister to provide the laboratory, 
nothing happened for some time, when one evening 
the Prime Minister came into the Club, went up to 
Threlfall and said, “ Well, Dick, Tve done the square 
thing by you at last ; Tve put your laboratory on the 
Estimates. WeVe just been beaten on a division and 
are going out, so the other fellows will have to pay.” 
The result was that Threlfall got a physical laboratory 
which at the time was one of the finest in the world, and 
which he soon made into a very active centre of scientific 

Very soon after I became Professor I was fortunate 
enough to persuade H. F. Ncwall (later Professor of Astro- 
Physics in Cambridge) to come to work in the Laboratory, 
and for some time we researched together. One of our 
researches, which led to very pretty experiments, was on 
the production of vortex rings by drops of one fluid fall- 
ing through another. When Threlfall went to Australia 
Newall succeeded him as Assistant Demonstrator. In 
1887 W. N. Shaw, who with Glazcbrook had organised 
the teaching of practical physics in the Laboratory and had 
with him directed the teaching of this subject for seven 
years, accepted a Tutorship at Emmanuel College. His 
new duties made too great demands on his time to permit 
of his continuing his work as Demonstrator, involving as 
this did attendance at the Laboratory for practically the 
whole of every other day. He was prevailed upon, 
however, to continue the courses of lectures on physics 
which he had given for many years, and he continued to 
lecture every term until he left Cambridge in ipoo to 
become Superintendent of the Meteorological Council. 
He was succeeded as Demonstrator by Newall in 1887, 


who held office until 1900, when he left the Laboratory 
to take charge of the large telescope which his father had 
left to Cambridge University. When Newall was made 
Demonstrator, L. R. Wilberforce, later Professor of 
Physics at Liverpool University, succeeded him as Assist- 
ant Demonstrator, and when Newall ceased to be Demon- 
strator Wilberforce succeeded him again. I cannot refrain 
from quoting an account given by Wdberforce of the 
relations between them, because it is so true and so honour- 
able to both : “It was impossible to work under him and 
see not only his abifity as a physicist and as an organiser, 
but also his unfailing patience, kindness and good-humour 
to his subordinates and his students, without deriving in- 
struction and inspiration from his example ” (History of 
the Cavendish Laboratory , p. 355). 

Though lectures suitable for candidates for the ist M.B. 
Examination were given by Glazebrook, who was lecturer 
in physics at Trinity College as well as a University Demon- 
strator, there was no teaching in practical physics suitable 
for these students until 1887, and no practical work in the 
examinations. About this time a short oral examination 
was added as an experiment, and revealed that the know- 
ledge of physics possessed by the candidates was peculiar 
though not extensive. It furnished the examiners with a 
crop of “ howlers with which they entertained their 
friends for long after. In 1887 T. C. Fitzpatrick was 
appointed Assistant Demonstrator, and I was fortuntate 
enough to induce him to undertake the organisation of 
the teaching of practical physics to medical students. At 
first the classes were small enough to be taken by one man, 
and did not take up much room in the Laboratory. 
They grew, however, very quickly, and in about a year 



L. R. Wilberforce was associated with Fitzpatrick. The 
attendance got so large that it was impossible to accom- 
modate the students in the Laboratory, and we had to look 
out for a new home. We found one at last in a corrugated 
iron shed which had been used as a dissecting-room. It was 
not, to begin with, all that could be desired, for such a 
nauseating odour clung to it that Fitzpatrick and Wilber- 
force had to exliaust all the resources of physics and 
chemistry to dispel it. The Laboratory boy was so terri- 
fied by fear of the ghosts of the former inhabitants that it 
was long before he could be persuaded to stay in the room 
unless someone was with him. When these difficulties 
had been overcome, the room proved well suited for its 
purpose. It was big enough to hold l^trgc classes, a most 
important point when the time-table is as crowded as that 
of a medical student. The classes were held hero until a 
new south wing was added to the Laboratory in 1894. 
This contained a very large room designed and well 
equipped for large classes; in this the M.B. classes have 
been given ever since it was opened. 

Glazebrook gave up the lectures to medical students in 
1890 on becoming the Principal of University College, 
Liverpool. The lectures were continued by J. W. Cap- 
stick, who had succeeded him as Lecturer in Physics at 
Trinity College, and when he became Junior Bursar of 
Trinity in 1898, Fitzpatrick undertook the lectures as well 
as the demonstrations to medical students ; from that time 
imtil he became Vice-Chancellor of the University in 
1916 he had the entire management of this department 
of the Laboratory : he made a great success of it, and his 
work was of outstanding importance to the progress of 
the Laboratory. This is far from being the only obliga- 
tion we are under to Fitzpatrick. Of the many gifts 


which have been received by the Laboratory, none have 
been more useful than the apparatus for producing hquid 
aiTj which he presented to the Laboratory in 1904. 
Many of the most important researches which have been 
made in the Laboratory would have been impossible 
without its aid. 

The number of science students in Cambridge increased 
rapidly after 1885. The pressure on the space in the 
Laboratory was very great, but it was removed in 1896 
when a new wing to the south was opened. The greater 
part of the cost was borne by the Laboratory, which 
provided ^2000 from the accumulation of fees from 
students attending the classes. In this wing there is 
a very large room used for the elementary classes in 
practical physics, for examinations in practical physics for 
the Natural Science Tripos and for entrance scholarships 
to the Colleges. Besides this there was a new lecture- 
room, cellars for experiments requiring a constant tem- 
perature, and a private room for the Professor. The 
increase in the number of students required an increase 
in the staff, as we always tried to have one Demon- 
strator for, at most, twelve students. An additional 
University Demonstratorship was founded whose salary 
was paid wholly from Laboratory fees, and S. Skinner 
was appointed to this in 1891, and C. E. Ashford and 
W. C. D. Whetham (now Sir Wdham Dampier, F.R.S.), 
were appointed Assistant Demonstrators about this time. 
W. N. Shaw, who had been appointed Assistant Director 
of the Laboratory and had been University Lecturer 
for thirteen years, left Cambridge in 1900 on his appoint- 
ment as Secretary to the Meteorological Council. It 
was decided to aboHsh the post of Assistant Director 
and create a new Lectureship, and G. F. C. Searle and 



C. T. R. Wilson were appointed to the two Lectureships. 
Searle only retired in 1935 and C. T. R. Wilson in 1925, 
when he was elected to the Jacksonian Professorship. 

The financial arrangements in force during my Pro- 
fessorship were that the University paid the salary of 
the Professor ; of two University Lecturers, ^^50 each ; 
of two University Demonstrators, -/^Too each, and of 
two Assistant Demonstrators, ^60 each. The University 
Lecturers and Demonstrators paid by the University 
were not nearly sufficient to provide satisfactory teach- 
ing for the large number of students in the Laboratory, 
and it was necessary to provide other Lecturers and 
Demonstrators whose salaries were paid by tlic Laboratory. 
At the end of my tenure this cost about ;,(^f500 a year. 
In addition to the payment of some salaries by the Uni- 
versity, the Laboratory received from the Museum and 
Lecture Rooms Syndicate jQ2jo per annum. The Labora- 
tory had also to pay the wages of the staff of the workshop 
— and also for the apparatus required for teaching and 
research, stores and material. 

The income of the Laboratory came from fees for 
lectures and demonstrations, and from the University and 
Colleges for examinations in practical physics held in the 

The distribution of these fees so as to provide for all 
the varied activities of the Laboratory was left in the 
hands of the Professor. This method is a rough and ready 
one, but I think, under the circumstances prevailing at 
the time, it was the most economical and efficient that 
could have been adopted. It was the method that had 
been in force since the foundation of the Laboratory. 
The fact that the greater part of the income of the Labora- 


tory comes from students’ fees is an inducement to make 
the lectures and demonstrations as attractive as possible, 
and to start new ones as soon as there is a demand for 
them. The increase in the Laboratory expenses is not in 
direct proportion to the number of students. There are 
some overhead charges which remain the same, and so 
the profit increases with the number of students. Another 
advantage is that it is possible with this system to wait 
until an instrument is wanted before buying it. In the 
more usual practice, when the University takes the fees 
and makes a grant to the Laboratory for apparatus, unless 
you spend the money in the year for which the grant is 
made, the authorities responsible will thmk that the grant 
is greater than you need and reduce it. When the fees 
are at the disposal of the Professor, he can choose his own 
time when to spend the money. He may in time ac- 
cumulate a considerable sum, and my experience is that 
the most useful instrument a laboratory can possess is a 
good balance at the bank. You may in this way have at 
hand a much greater sum than the annual grant, with 
which you can equip the laboratory with the instruments 
required to follow up new lines of research, such as radio- 
activity or positive-ray analysis. The money is ready at 
hand, and you have not to spend months in getting it 
from some Committee or Institution. An illustration of 
this is that, when the work of the Laboratory was suffering 
severely from overcrowding, a new wing was built for 
^2000, the result of twelve years’ saving at the Laboratory. 
At that time (1896), the poverty of the University was so 
great that I was convinced from enquiries that I made that 
they would not provide this sum. Next with regard to 
economy. I have gone carefully into the question of 
what was the cost of the original research going on in the 



Laboratory. Taking the accounts for the year 1912-13, 
the year before the war broke out, and the last in which I 
was responsible for the research in the Laboratory, I find 
that an outside estimate for the extra expense incurred 
by the Laboratory for the researches would be ^ 550 , and 
there were forty research students. The cost of instru- 
ments required for the type of research then pursued 
in the Laboratory was very much less than that of those 
needed in some of the more recent developments of 

In those days the cost of researches done in the Labora- 
tory had to be paid for by the Laboratory itself. The 
only aid it could get from outside was from the Govern- 
ment grant of a year for research, which was 

administered by the Royal Society and had to suffice for 
the needs of all the sciences, so that there was not much 
available for any particular science. There has been a 
great improvement since then. The Royal Society in the 
last twenty-five years has received very generous donations 
and bequests, so that in addition to the Government grant 
it has considerable funds which can ' be applied to the 
purchase of apparatus. The Department of Scientific and 
Industrial Research has made many grants for this purpose ; 
some of the great City Companies and some Colleges, my 
own among the number, have received bequests which 
can be applied to aid the researches done by its members. 
And it was only the other day that Sir Herbert Austin 
gave the magnificent donation of ^£250, 000 to the funds 
of the Cavendish Laboratory. 

It is not, in general, the first discovery of some quite 
new physical phenomena that is costly. For example, the 
discovery of X-rays by Rontgen, of radium by the Curies, 
the long-continued experiments of C. T. R. Wilson on the 


formation of drops on particles cliarged with electricity, 
cost quite insignificant sums. Discoveries such as these 
were due to what cannot be bought : to keen powers of 
observation, to physical insight, to an enthusiasm which 
does not falter until the diifficulties and discrepancies which 
attend on pioneering work are overcome. 

When first the discovery is made, the effects observed 
are generally very small, and require a succession of 
lengthy experiments to obtain trustworthy results. It is 
the attempt to get larger effects that is so expensive. It 
may mean spending many thousand pounds in making 
powerful magnets or in producing electromotive forces of 
hundreds of thousand volts, or in obtaining large suppHes 
of radium. Such money is, however, well spent, for it 
enables us to obtain new knowledge much more quickly 
and with greater certainty. 

The Cavendish Laboratory was the first of the labora- 
tories in the University where the benefactor defrayed the 
whole cost of the building, and it remained the only one 
until well on into the present century, for though a new 
chemical laboratory and the engineering laboratory had 
been built before then, the cost was borne wholly by the 
University. After the war the University was fortunate 
enough to receive many very large donations, and some 
of these were for building laboratories. Thus a large 
physiological laboratory was given to the University by 
the Drapers’ Company. The trustees under the will of 
Sir William Dunn presented to the University 150,000 
for, along with other objects, providing a laboratory for 
biochemistry and establishing a Professorship in that 
subject. In 1919 the chemical laboratory received for the 
extension of the laboratory ^210,000 from a number of 
prominent oil companies. The Rockefeller Foundation 


provided the University vv^ith a very large pathological 
laboratory ; the Goldsmiths’ Company, a laboratory for 
metallurgy ; the Mond Laboratory, for research in magnet- 
ism, came from the funds provided by the Royal Society ; 
and the Low Temperature Laboratory was financed by 
the Board of Invention and Research. The Institute 
of Parasitology was created by the munificence of 
P. A. Molteno. I have mentioned only gifts for labora- 
tories. Since the war twenty-six Professorships in many 
branches of science and literature have been created by 

In 1895 the University opened its doors to graduates 
of other universities whether at home or abroad, and in 
exceptional cases to those who were not graduates of any 
university, who wished to come to Cambridge for research 
or advanced study. These had to satisfy a Committee 
appointed for the purpose tJiat they were qualified to do 
research, and that the research tliey contemplated was one 
which could be profitably carried out in the laboratory 
in which they proposed to work. They were entitled to 
the B.A. degree and certificate for research if, after two 
years’ residence in Cambridge, they submitted to the Com- 
mittee work which, in its opinion, was ‘‘ of distinction as a 
record of original research ”. If they had only resided one 
year when they submitted a thesis wliich obtained this 
verdict, they were entitled to the certificate, but not to 
the degree until they had completed another year’s re- 
sidence. This had such a great effect on the fortunes of 
the Laboratory, that 1895 is a convenient halting-place in 
a review of its progress. 

After my appointment Glazebrook and Shaw con- 
tinued dieir lectures for the first part of the Natural 


Sciences Tripos, and for this part I also gave three courses, 
one in the Michaelmas Term on the properties of matter, 
and a course on electricity and magnetism extending over 
the Lent and Easter Terms. For Part II, I gave two courses 
of lectures, one in the Michaelmas, one in the Lent Term, 
and in the Easter Term Glazebrook and I set papers for 
those who were going in for this examination at the end 
of the term. In addition, I had a class in the differential and 
integral calculus for students who were hampered in the 
study of physics by their ignorance of this subject. There 
were plenty of lectures in the Colleges on it, but 
they were given by mathematicians for mathematicians, 
and were not concerned with the applications of mathe- 
matics to other subjects. The difference was forcibly 
expressed by one of my students who was unable to attend 
my classes, and who went to College lectures. I asked 
him after about three weeks how he was getting on, 
and he said he had had to give them up because he had 
gone to them to learn how to use ‘‘ Taylor’s Theorem ” 
(a fundamental part of the subject), and the Lecturer had 
talked about nothing but cases where Taylor’s Theorem 
could not be used. Later on these lectures were given by 
L. R. Wilberforce, and when he left by J. S. E. Townsend 
(then a research student), now Professor of Physics at 

Besides attempting to give students of physics some 
knowledge of mathematics, we organised some demon- 
strations to enable mathematical students to get some 
realisation of the physical subjects, heat, mechanics and 
hydrostatics, included in the Mathematical Tripos. The 
teaching of mathematical students in physics had been en- 
tirely bookish, and many of them had had no opportunities 
of seeing that their physics corresponded to anything real. 

129 K 


The demonstrations brought to liglit some interesting 
points. We found many eases where men who could solve 
the most complicated problems about lenses, yet when 
given a lens and asked to find the image of a candle flame, 
would not know on which side of the lens to look for the 
image. But perhaps the most interesting point was their 
intense surprise when any mathematical formula gave 
the right result. They did iK)t seem to realise it was any- 
thing but something for which diey liad to write out 
proofs in examination papers. The time-table of the 
mathematical students in those days was so crowded that 
it was difficult to find a time when they could attend the 
demonstrations. The classes were small and were given 
up after two or three years. 

The lectures for Part 11 of tlie tripos were much 
strengthened towards the close of this period by a course 
on electrolysis by Mr Dampicr Whetham (now Sir 
William Dampicr, F.R.S.), wlio had made important 
researches on this subject in the Laboratory. 

The Cavcndisli Physical Society was founded in 1893 ; 
it held fortnightly meetings preceded by tea in term time. 
Its primary object was the discussion of recently published 
papers on physics. Besides helping to keep the workers 
in the Laboratory abreast witli recent work in physics, it 
gave them an opportunity of acquiring practice in lectur- 
ing, for the majority of the reports on papers were given 
by the students themselves. The discussions which fol- 
lowed the reading of the report helped to clear up diffi- 
culties, and not infrequently suggested subjects for further 
investigation. Again, a student who had completed a 
piece of research generally gave an account of the results 
he had obtained before publishing them. This was often 
very helpful, as it enabled him to see the points he had not 



made clear, and which would require further explanation 
before the paper was pubHshed. 

During the first two years of my Professorship 
Olearski, Natanson and H. F. Reid were working in the 
Laboratory. They were the first of a long series of students 
from foreign universities who have come to work in the 
Laboratory ; they all attained distinguished positions as 
physicists. It is beyond the scope of this book to give 
an account of the many researches that were made in the 
Laboratory in this period : I must confine myself to a 
small number which contain points of general interest. 
H. L. Callendar’s career at the Laboratory was in some 
respects the most interesting in all my experience. He 
was on the classical side when at school and did not do 
any physics. As an undergraduate he took a First Class 
in classics in 1884 and one in mathematics in June 1885. 
He came to work in the Laboratory in the Michaelmas 
Term in that year. He had never done any practical work 
in physics, nor read any of the theory except in a very 
casual way. He had not been in the Laboratory for more 
than a few weeks when I saw that he possessed to an 
exceptional degree some of the qualifications which make 
for success in experimental research. He was a beautiful 
manipulator, and dehghted in making the results he 
obtained as accurate as was possible with the instrument 
he was using. The problem was to find a subject for his 
research which would give full play to his strong points 
and minimise as much as possible his lack of ej^rience. 
I knew from the ability he had shown as an uame^raduate 
that, whatever the subject rni^Et D^^b^P^yuld h^e no 
difficulty m mastering the literatu^p ^outa t. ^ji^^^ed 
to me that the most suita ble 


centred on the accurate measurement of electrical re- 
sistance. Much work had been done in this subject, and 
methods evolved which gave results of great accuracy. 
The instrument required — the galvanometer — had been 
made so reliable that the use of it did not require a long 
apprenticeship. The resistance of a platinum wire depends 
upon its temperature, so that if the resistance of the wire 
at different temperatures is known you can, by measuring 
its resistance, determine its temperature. The wire acts 
like a thermometer, and since platinum only melts at a 
very high temperature, it can be used for measuring 
temperatures at which a mercury thermometer would be 
useless. Siemens had actually constructed a thermometer 
on this principle, but this was found to have grave defects 
which made accurate determinations of temperature im- 
possible. The simplicity and convenience of using a piece 
of wire as a thermometer was so great that it seemed to 
me very desirable to make experiments to sec if the failure 
of Siemens’ instrument was inherent to the use of platinum 
as a measure of temperature, and not to a defect in the 
design of the instrument. Callendar took up this problem 
with great enthusiasm and showed that, if precautions are 
taken to keep the wire free from strain and contamination 
from vapours, it makes a thoroughly reliable and very 
convenient thermometer. This discovery, which put 
thermometry on an entirely new basis, increasing not only 
its accuracy at ordinary temperatures, but also extending 
this accuracy to temperatures far higher and far lower than 
those at which hitherto any measurements at all had been 
possible, was made with less than eight months’ work. I 
had very httle to do with it beyond seeing how it was 
going on from day to day, and encouraging him when 
he was disheartened by the set-backs which occur in all 


researches. The results of the investigation were set forth 
in a paper communicated to the Royal Society in 1886 
and pubhshed later in their Transactions. He was a suc- 
cessful candidate for a Fellowship at Trinity College in the 
autumn of 1886, and sent in this paper as the dissertation 
which has to be submitted to the Electors to the Fellow- 
ships. The decision of the Electors is influenced far more 
by the merits of the dissertation than by any other con- 
sideration, and Callendar was elected though this was his 
first attempt. Candidates for Fellowships may try in any 
of the three years between taking the B.A. degree and 
being eligible for the M.A., and it is somewhat unusual 
for a candidate to be elected at his first opportunity. 
Thus, starting with no previous knowledge of physics, 
with no experience in making physical measurements, 
Callendar had in a few months obtained results of abso- 
lutely first-rate importance, an importance which cannot 
be gauged even by their pubhcation in the Philosophical 
Transactions or by their leading to the election to a Fellow- 
ship. They gave to the physicist a new tool by which 
he could determine temperatures with an ease and accuracy 
never obtainable before. They were also of the utmost 
importance to industry ; they enabled the steel-maker to 
measure the temperature of the molten metal in his vat, 
the brewer the temperature of his brew ; they replaced 
guess-work by accurate measurement and cookery by 
science. Callendar’s case raises the question whether the 
very large amount of time devoted in our universities to 
the performance of experiments by students attending the 
advanced demonstrations in practical physics is either 
necessary or desirable. I am inclined to think that it is 
not, provided the candidate is a good manipulator and is 
an able man. I think such a one, if he had to use, in the 



research he was contemplating, some new type of instru- 
ment, would not be very long before he had mastered 
its technique. There have been many great physicists who 
never attended any demonstrations in practical physics — 
Joule, Stokes, Kelvin, Rayleigh, Maxwell, to take only 
English examples — and I am not sure that they lost much 
by the omission. 

Calleiidar continued his researches on the connection 
between resistance and temperature at the Cavendish 
Laboratory until he left it in 3890 to be Professor of 
Physics at the Royal Holloway College ; he went on 
with them afterwards in the laboratory at that College, 
and later still in the laboratory at McGill University, 
Montreal, where he had been made Professor of Idiysics. 
A comprehensive account of these is contained in his paper 
in the Philosophical Magazine for February 1899. In this 
he says that his experiments suggest tliat the resistance of 
certain metals vanishes at a temperature appreciably above 
the zero of absolute temperature. That this is the case 
has been proved conclusively by the experiments made by 
Kamcrlingh Onnes and others at the low temperatures 
which can be obtained by the use of liquid helium and 
liquid hydrogen. 

In addition to his other achievements Callendar, when 
in Cambridge, invented a new system of shorthand ; he 
went into it very thoroughly, measuring accurately the 
time it took to write symbols of different shapes and 
selecting the fastest. I learnt the system and found it 
exceptionally easy to read and very useful for making 
rough notes, as it was not necessary to transcribe them 
into long hand. 

CaUendar became a Fellow of the Royal Society in 




W. C. DampierWhetham (now Sir William Dampier) 
made important researches in this period with his new 
method of measuring the velocity of ions in hquid electro- 
lytes, and also on the slipping of Hquid when moving in 
contact with soHd surfaces. 

Some very notable experiments on the potential differ- 
ence required to produce electric sparks at different lengths, 
and through gases at different pressures, between two large 
parallel electrodes were made by J. B. Peace. He found 
that when the pressure was kept constant and the dis- 
tance between the plates gradually diminished, though at 
first the sparking potential diminished, the diminution 
ceased when the distance had been reduced to a certain 
value, and after this the sparking potential increased as 
the distance diminished, so that it was impossible to get 
a spark unless the potential exceeded a certain value, 
about 300 volts in air. Similarly, if the distance is kept 
constant and the pressure diminished, you cannot get a 
spark unless the potential difference exceeds 300 volts. 

At the end of this period C. T. R. Wilson began to 
work at the Laboratory and pubHshed in 1895 the first of 
his papers on the formation of clouds, the beginning of a 
long course of researches which have been of vital im- 
portance for the progress of modem physics. 

During this period I made experiments on the resist- 
ance of electrolytes, and the specific inductive capacity of 
dielectrics when under the influence of the very rapidly 
alternating currents produced by the discharge of a Leyden 
jar. I also made a long series of experiments on the 
passage of electricity through gases when the electric force 
producing the discharge was obtained by the forces due 
to electromagnetic induction, produced when the rapidly 
alternating currents due to the discharge of a condenser 



pass til rough a coil of wire. When a glass bulb containing 
gas at a low pressure is placed inside the coil, the electro- 
magnetic induction produces electric forces inside the bulb 
which arc able to produce a discharge through the gas. 
The discharge passes as a circular ring, since the lines of 
electric force inside the bulb due to electromagnetic 
induction are circular. There are in this ease no electrodes 
in the gas ; the discharge is reduced to its simplest form 
and never has to pass from the gas to another substance. 

I found these experiments very interesting. The dis- 
charge is, under proper conditi{)ns, bright and very beauti- 
ful, and the method has valuable applications to the study 
of many important questions in the discharge of electricity 
through gases, to the clfcct on tlic electrical and magnetic 
qualities of bodies of very rapid alternations in electric 
forces acting upon them, and to spectroscopy. 

I made, too, experiments on the pas.sagc of electricity 
through hot gases, which supported the view that some 
kind of dissociation was associated with the conductivity 
of gas and that the current was carried by charged particles. 

The year 1895 hs one of the most important years in 
the history of the Cavendish Laboratory, for then a 
regulation came into force by which graduates of other 
universities were admitted to Cambridge as “ Research 
Students ”, and if after two years’ residence at Cambridge 
they submitted to a Committee a thc.sis containing an 
account of their researches they were entitled to a Cam- 
bridge degree, provided the Committee declared it was 
“ of distinction as a record of original research At 
first the degree was that of Master of Arts, but after a few 
years’ trial this was replaced by Ph.D. (Doctor of Philo- 
sophy), a new degree created by the University for their 


benefit. It was represented to the University that since 
the M. A. degree did not entide a man to be called “doctor"’, 
our students were at a disadvantage when competing for 
teaching posts with those who had been to a German 
university and had obtained the Ph.D. degree. This 
poHcy of creating “ Research Students ” had a very 
auspicious start, for at the beginning of October 1895, when 
the regulations first came into force, Ernest Rutherford, 
now Lord Rutherford, O.M., F.R.S., and J. S. E. Town- 
send, now F.R.S., and Wykeham Professor of Physics at 
Oxford, came to the Laboratory to enter as research 
students within about an hour of each other ; and not 
long afterwards J. A. McClelland, later F.R.S. and Pro- 
fessor of Physics in the University of Ireland until his 
death. Rutherford, came from Canterbury College, New 
Zealand ; Townsend from Trinity College, Dublin ; and 
McClelland from Queen’s College, Galway. 

Rutherford began his work at the Laboratory by 
working at wireless telegraphy, using a detector which 
he had invented before leaving New Zealand ; it worked 
on the principle that a piece of soft iron wire, magnetised 
to saturation, loses some of its magnetism when placed 
inside a solenoid through which the rapidly alternating 
currents obtained from the wireless pass. He held, not 
long after he had been at work in the Laboratory, the 
record for long-distance telegraphy, as he had succeeded 
in sending messages from the Laboratory to his rooms 
about three-quarters of a mile away. Townsend began 
a research on the magnetic properties of the salts of iron 
of various types, which led to very interesting results. 
He found that the magnetism due to the same mass of 
iron was the same in all the ferrous salts and also in all the 
ferric, but the magnetism in the ferrous was not the same 



as in die ferric, while in salts like die ferricyanides iron 
was hardly magnetic at all. 

The number of research students increased so rapidly 
after the introduction of die new regulations that in a 
few years they became wliat tlicy have been ever since, a 
characteristic feature of the Laboratory, giving it quite a 
cosmopolitan tone. We have had among them students 
from practically every important university in Europe, Asia, 
Africa and America. Along with Cambridge students 
staying on after taking their degrees, there are generally 
graduates of most universities in Ch’cat Britain and the 
Dominions, some of them holders ol the “ rSsr Exhibi- 
tions”, graduates from the United States, and frequently 
one or more professors of American universities spending 
their “ Sabbatical Year” in research, and graduates from 
German, French, Russian and Polish universities. The ad- 
vantage gained by our own students by dieir intercourse 
with men of widely diderent training and exjicricncc, of 
different points of view on political, social and scientific 
questions, of very different temperaments, can, I think, 
hardly be overestimated. They gain catliolicity of view 
and some of the advantages they would gee by residence 
in the universities from which the research students came. 
To give them better opportunities of getting to know each 
other, I arranged that we should meet for tea in my room 
every afternoon. Personally I found these meetings very 
delightful, and I made it a point to arrange my engagements 
so that I could attend them. We discussed almost every 
subject under the sun except physics. 1 did not encourage 
talking about physics because the meeting was intended 
as a relaxation for men working all day at physics, and 
also because the habit of talking “ shop ” is very easy to 
acquire but very hard to cure, and if it is not cured the 


power of taking part in a general conversation may 
become atrophied for want of use. If the morning 
papers contained an account of some striking event at 
home or abroad it was generally mentioned at our tea- 
party, and very frequently we fotmd that there was 
someone who knew well the place where the event 
happened, who was able to throw fresh Hght upon it and 
make it seem much more vivid than the reading of any 
number of telegrams. I have, for example, when a Presi- 
dential Election was taking place in the United States, 
heard Repubhcans and Democrats fighting their battle with 
great vigour, and have felt that I learnt far more about 
American pohtics by listening to them than by reading 
columns in the newspapers from special correspondents. 

The students from other universities were surprised 
and at first irritated by the restriction put upon them by 
the College regulations and particularly by the one which 
obliged them to be in their rooms before a certain time. 
No such restriction was in force in any of the universities 
from which they came, and they said it was like going 
back to the nursery and being sent to bed at 7 o’clock. 
Another matter which was a great puzzle to them 
was the duties performed by their College Tutor. In 
Cambridge there is a distinction between the office of 
Tutor and that of Lecturer. The Tutor is supposed to 
be in loco parentis to his pupils_, and acts as the connect- 
ing hnk between the College and the parents. He 
generally holds a Lectureship in some subject, but only 
those of his pupils who are students of this subject go 
to his lectures. None of the College Tutors to whom 
they were assigned ever lectured on physics, and they could 
not understand what was the use of a Tutor. One of the 
research students thought he would take a busman’s holi- 



day and spend his leisure in a research into what a Tutor did. 
He proceeded to make experiments. He went to his Tutor 
and asked him for permission to go to the theatre : the 
Tutor told him he did not need any such permission. Then 
after an interval he asked the Tutor to order a supply of 
coals for the winter to be sent to his lodgings. The Tutor 
said it was none of his business. He went on like this 
and at last received his term’s bill from the Tutor. He 
was quite pleased and said, I have solved my problem : 
the Tutor sends in the bill 

By 1898 the number of students had become large 
enough to justify the celebration of the beginning of the 
Christmas Vacation by a dinner. This was the first of a 
series which has gone on without interruption (except in 
war-time) until now. They arc largely attended and 
highly valued since they enable old research students to 
meet old friends and talk of old times, and help to establish 
a connection between past and present research students. 
The first of these dinners was held in December 1898 at 
Bruvet’s Restaurant in Sidney Street. During the songs 
after the dinner the proctors came to enquire what the 
proceedings were about. They did not come into the 
room where we were dining, being, I suppose, im- 
pressed, and I have no doubt mystified, by the assurance 
of the landlord that it was a scientific gathering of research 
students. A notable feature of these gatherings was the 
songs specially composed for these occasions by research 
students. Mr A. A. Robb, the author of a well-known 
book on the metaphysics of mathematics called Space and 
Time, showed that he could tread a lighter measure with 
equal success, though I am afraid it requires more mathe- 
matical knowledge than I can assume to be possessed by 
all my readers, to appreciate the skill with which he has 


turned Maxwell’s equations into the chorus of a song to 
the tune of The Interfering Parrot ” in The Geisha : 
dy by dy less d^ by dz is equal KdX/dt 

While the curl of (X, Y, Z) is the minus djdt of the vector (d, h, c), 

Mr Craig Henderson, who was, I think, present at the 
first dinner, was President of the Union in the Lent Term 
of 1898, the only Cavendish research student who has 
obtained this distinction. 

Craig Henderson, while he was in Cambridge, saw a 
good deal of the ordinary undergraduate life, a thing 
which is not easy for a research student to do. He does 
not go to the same lectures as the ordinary student nor, 
since he is working in the laboratory all day, can he take 
part in their sports : the laboratory takes the place of the 
College, but it does not give him as good opportunities 
for making friendships with men of different interests, with 
different views on social, political, and religious matters, and 
with different experiences of life. It does, however, offer 
better opportxinities of making friends with men of differ- 
ent nationalities. The research students are so enthusiastic 
about their work that, besides attending the meetings of 
the Cavendish Physical Society, they form societies of 
their own, and discuss fortnightly or weekly the recent 
advances made in physical science. This, though laudable 
in itself, does diminish the opportunities they have for 
meeting other than research students, and prevents them 
getting from Cambridge all that it could give. It is easy, 
however, to exaggerate this, so much depends upon the 
man himself. Some are bom specialists, others are bom 
with the gift of making friends and for taking an interest 
in a wide range of subjects. And after all, it is not 
only the research students who are specialists ; there are 
students who speciaHse in some kind of sport and take 



little or no interest in anything else. Others specialise in 
the Union and take no interest in anything but debates ; 
others in the cinema, and confine their interests to film stars. 

The workers in the Laboratory during the period under 
consideration, 1896-1900, included L. Blaikie, G. B. Bryan, 
J. B. B. Burke, W. Craig Henderson, J. Erskine Murray, 
J. Henry, P. Langevin, J. G. Leathern, R. G. K. Lempfert, 
Theodore Lyman, J. A. McClelland, J. C. McLennan, 
C. F. Mott, 1 . Nabb, H. F. Ncwall, Vladimir Novak, 
R. B. Owens, J. Patterson,}. B. Peace, O. W. Richardson, 
A. A. Robb, W . A. D. Rudge, E. Rutherford, G. F. C. Searle, 
G. A. Shakespeare, W. N. Shaw, S. Skinner, S. W. J. 
Smith, Hon. R. J. Strutt, J. Talbot, J. S. E. Town- 
send, J, H. Vincent, E. B. H. Wade, G. W. Walker, 
W. C. Dampier Whetham (now Sir William Dampicr), 
R. L. Wills, C. T. R. Wilson, H. A. Wilson,}. Zclcny. 

The merits of the research students were soon re- 
cognised by the Colleges. Trinity College elected 
Rutherford to the Coutts Trotter Scholarship in 1898 
and Townsend to a Fellowship in 1899. Emmanuel, 
Caius, St. }ohn’s and Trinity have been foremost in 
encouraging research students and research, and each of 
these offers each year a studentship open to any graduate 
of any university other than Cambridge. These, however, 
are not confined to students of physics. 

In the period between the beginning of this century 
and the war the number of research students steadily in- 
creased, and in addition many distinguished physicists 
came from abroad and spent a year in research at the 
Laboratory. Among these were Professor Bumstead 
from Yale, Professor Carlhclm-Gyllcnskold from Stock- 
holm, Professor Erikson from Minnesota, Professor 
Huff and Professor Mackenzie from Bryn Mawr, 


Professor L. T. More from Cincinnati, Professors Nichols 
and Hull from Dartmouth College, U.S.A. ; Professor 
Karl Przibram from Vienna ; Professor Smoluchowski, 
University of Lemberg ; Professor Vegard, University of 
Christiania. All arrived in the first decade of the century. 
They formed a very welcome addition to our society ; 
they were the most agreeable of companions and we got 
from them first-hand information of the methods of 
teaching physics in their own country, and learned which 
parts they thought from their own experience were satis- 
factory and which required alteration. 

The American Professors were keenly interested in the 
difference between life at Cambridge and that at an 
American university. The late Professor Bumstead, 
who during the war came to London as Haison officer 
between our Board of Invention and Research and a 
similar body in America, to enable each country to become 
acquainted with the improvements and inventions made 
by the other, has given his impression of these in a letter 
pubhshed in the History of the Laboratory, from which 
I give a few extracts : ‘‘ With regard to the University 
as a whole, one thing which struck me was the essentially 
British way in which it has utihsed survivals of the past, 
not sweeping them away because they were or might 
become abuses, but adapting them to modern conditions 
in such a way that you have a better instrument for the 
presentation and enlargement of knowledge than we can 
make here with the ground all clear for the ' most modem 
improvements Two illustrations of what I mean 
wiU suffice. One is the division of the University into 
Colleges, which seems to me to be of enormous advantage 
to the social fife of both xmdergraduates and dons and to 
their broad intellectual development. In this country we 



have schools of engineering, law, medicine and divinity, 
the liberal arts and so on. Tlic scK'ial groups tend to 
follow these lines with a distinctly narrowing influence. 
I think you have a much better arrangement and yet I 
cannot sec how it could be made to order. It is only 
history and tradition that make Trinity, St. John’s and 
Caius all different and yet parts of one whole. 

“ Another survival which I envy you is the system of 
Fellowships, which 1 suppose was the source of some abuse 
in the past. But I believe it is on the whole the best 
means of promoting research and sound scholarship which 
could be devised. ... If you can keep your Fellowship 
system from being reformed too much, you will be 
fortunate among tlic universities of the world.” “ Your 
social life struck me as much richer and fuller than ours, 
really we seem to work too much to enjoy each other’s 
society and yet we do not get so much done as you. I 
don’t understand it altogether : a laboratory in this 
country in which nobody ever began work before to a.m. 
or worked later than 6 in the evening would serve as a 
terrible example of sloth and indolence. 1 do not see 
how you can get so much work done and yet have time 
to live so pleasantly and unhurriedly.” “ 1 have never seen 
a laboratory in which there seemed to be so much inde- 
pendence and so little restraint on the man with ideas.” 

The election of a man of science to the Fcllowslhp of 
the Royal Society of London, the most important scientific 
society in this country, is a proof that his work has been of 
exceptional importance and merit. This honour has been 
conferred upon many of those who worked in the Cavendish 
Laboratory while I was Professor. See Appendix. 

A large number of students who worked at the 
Cavendish Laboratory whilst I was Professor were elected 


to Professorships in Physics in this and other countries. 
The list of universities in which my pupils have held 
Professorships is given in the appendix ; when more 
than one Cavendish student has held the Professorship, 
the number is enclosed in brackets. 

In 1902 a portrait of myself by Mr Arthur Hacker, 
R.A., was presented to the Laboratory by those who had 
been, or were at the time, my students. I think it is the 
portrait I like best. It was painted in very few sittings, 
as I had to sail to give some lectures at Yale, and there 
were very few dates which suited both the artist and 
myself. This is an example of what has always been my 
experience, that a few sittings give better results than a 
great many. I have had twenty-five and twenty-seven 
sittings for other portraits, and have watched the picture 
gradually getting worse after each sitting. Perhaps the 
most successful of all was a bust by Mr Derwent Wood, 
R.A., now in the hbrary of Trinity College, for which I 
only sat for about forty-five minutes. 

The portrait by Mr Hacker hangs in the Laboratory. 
Another example of the generosity and goodwill of my 
old students came on my seventieth birthday when they 
gave me an address with 259 signatures, together with a 
large cigarette-box, which I am afraid i use too often. 
These were presented to me at a diimer, when speeches 
were made by several very old friends and pupils : Lord 
Rutherford, Professor Langevin, Dr. A. Wood, Sir Arthur 
Schuster, Sir Richard Threlfall and Dr. Horton. A 
charming present was also made to my wife, who was at 
the dinner. These expressions of goodwill touched me 
very acutely ; the remembrance of them is deHghtful. 
They recall the help, kindness and goodwill which it 
has been my good fortune to receive from everyone con- 

145 L 


ncctcd with the Laboratory, for more than fifty years. I 
owe to the Laboratory not merely the opportunities it has 
given me for indulging my scientific tastes in a way that 
would not have been possible in any other place. I owe 
to it besides many valued friends, and memories of friend- 
ships which can no longer be more than memories. 



Psychical Research 

I N the nineties, at the instance of F. H. W. Myers, I 
attended a considerable number of seances at which 
abnormal physical effects were supposed to be pro- 
duced. This was the only kind I went to see. I did not 
attend any demonstrations of thought transference, or 
those where the medium showed a knowledge of one’s 
personal affairs which she could not have acquired by 
natural means. The results were very disappointing ; at all 
but two of those I attended nothing whatever happened, 
and in the two where something did there were very 
strong reasons for suspecting fraud. The first of these 
was given by an American slate-writer, Eglinton, whose 
seances had received a good deal of attention from the 
Press. He claimed to be able to get messages written on 
slates under circumstances which precluded human agency. 
I went with Myers and Mr H. J. Hood, who at that time 
took a prominent part in psychical research, to his room, 
near, I think, to the Marble Arch. Eglinton took a slate 
which we were allowed to examine, and we found no 
reason to suspect that it was anything but an ordinary 
school slate. He then broke a small piece off a slate 
pencil, and placed the fragment on the top of the slate. 
We then sat down at a trestle table ; he sat at one end, I 
held his right hand with my left, and with his left hand 
he held the slate under the table. The piece of slate 
pencil was between the bottom of the table and the top 



of the slate. The room was not darkened in any way 
and all the proceedings took place in broad daylight. He 
then asked each of us tor a cjucstion wliich we should like 
the spirits to answer. Myers and Thxxi asked questions 
concerning spiritualism, I preferred a question to which 
I knew the answer, so I asked what county Manchester 
was in. We then sat for, I should think, a quarter 
of an hour without anything happening. Then he 
seemed to be seized with convulsions and it was all I 
could do to hold him up and prevent him from falling 
off the chair. He recovered in a short time, brought the 
slate from under the table, and on it was written in a 
sprawling hand with large ill-formed letters : Manchester. 
My view is that Eglinton thought there must be some 
catch in my very simple question, and that he knew that 
some English towns were counties in themselves and sup- 
posed, because I had asked the question, that Manchester 
was one of them. With regard to the w^ay in which the 
writing was done ; it is possible to write on. a slate either 
in the usual way by keeping the slate fixed and moving 
the pencil, or, though with much greater dilficulty, by 
keeping the pencil fixed and moving the slate. Thus, if 
he had managed to jam the piece of slate pencil in a crevice 
or depression on the lower part of the table, he might have 
been able to write without any considerable movement of 
the arm supporting the slate. 

A much more exciting and interesting experience was 
one with Eusapia Palladino, an Italian peasant woman who 
had been discovered by Professor Richet, a celebrated 
French physiologist, and who had shown very remarkable 
powers of producing abnormal physical effects in a series 
of seances she had with Professor Richet and Sir Oliver 
Lodge in an island in the Mediterranean under conditions 



which made fraud seem very improbable. Eusapia came 
to Cambridge in the Long Vacation of 1895, 3.nd stayed 
with the Myers. She held some seances and I was present 
at two of them. At the first, which began about 6 o’clock 
in the evening, Lord Rayleigh, Professor Richet, Myers, 
Richard Hodgson, Mrs Sidgwick, Mrs Verrall and myself 
were present, along with a few others whose names I have 
forgotten. We sat at a long table. Eusapia was at one 
end, Lord Rayleigh on her right, I on her left ; and Mrs 
Verrall was under the table holding her feet. There was 
a melon on a small table at some httle distance from that 
at which we sat, and it was part of the programme that 
the melon should be precipitated on to the table. There 
were heavy velvet curtains over the windows, and when 
the hghts were all put out it was pitch dark. We formed 
the circuit by clasping hands in the usual way, and sat 
like this for a considerable time without anything happen- 
ing. Then Myers, who thought it good pohcy to en- 
courage mediums at the commencement of a seance, 
jumped up and said he had been hit in the ribs. The 
circuit was thus broken and it was perhaps a minute before 
it was re-formed. Hardly had we got seated when Mrs 
Verrall called out “ She’s pulled her foot back ”, and then, 
without an interval, “ Why, here’s the melon on my head ! ” 
What had happened was quite obvious : while the circuit 
had been broken and Eusapia was free she had reached out, 
got the melon, sat down and put it on her lap, intending 
to kick it from her knee on to the table. Now if you want 
to kick from the knee you begin by drawing the foot back. 
Eusapia had done this, but had been disconcerted by Mrs 
Verrall calling out, and had not got her kick in in time, 
and the melon had rolled off her lap on to Mrs Verrall’s 
head. She then set to work to retrieve the situation. 



Very soon after we had sat down again she began abusing 
me in a language (^f whicli J did not understand one word, 
but Richet, who understood lier, said she was accusinj> 
me of squeezing her Jiand and that she would not allow 
this. Instead of liolding her hand, all she would permit 
was that 1 might put the tips of my fingers on the back 
of her hand ; this was done. After a short interval she 
began to abuse Lord Rayleigh, and Richet said she was 
accusing him of squeezing her haiui and that, instead of 
holding hands, site would put the tips of her fingers on 
the back of his hand. 'This change, as was found out 
later by Mr Modgson, was the essence of her trick. She 
kept moving the hand I was touching backwards and 
forwards and I had to follow with my fingers. In this 
way she was able to make my fingers sli[) from the back 
of her hand either to her other hand or on to the back of 
Lord Rayleigh’s. In this case she would get both hands 
free, for I should think that I was pressing Etisapia’s hand 
when as a matter of fact 1 was pressing Rayleigh’s, and 
he would think he was still heiug pressed by Eusapia while 
in fact he was pressed by me. If she slipped my fingers to 
the back of Iier other hand and not to Rayleigh’s she would 
get one hand free. Certainly, soon after this change in 
the way of holding liands was made, tlic proceedings 
became very lively, chairs came down on tlic tabic with 
a bang, the table rose in the air ; at any rate the end near 
me did. Wc were hit on the back and dug in the ribs, 
and this went on for what seemed several minutes. After 
this was over she showed us another phenomenon which, 
unlike the first, was done witli a light in the room. It 
was not a very bright light, but good cmnigh to enable us 
to distinguish people and the position of the furniture. 
There was a window at one end of the room covered with 



a heavy velvet curtain. She sat down on a chair a few 
feet away from this with her back towards it. She made 
no objection to my looking between the curtain and the 
chair to see if there was a string or connection of any kind 
between them. I did not detect any, but the hght was 
not good enough to enable me to be certain that nothing 
was there. After we had been seated for a short time the 
curtain began to move and, looking hke a sail full of wind, 
reached Eusapia and then slowly fell back. It did not 
look as if it had been pulled by a string, at any rate by a 
single string, for if so it would have been pointed like a 
jelly bag instead of being round like a sad. As she was 
to give another seance on the next evening, I went to the 
house in the morning and asked Myers if I might fit up 
an arrangement to make sure there was nothing between 
Eusapia and the curtain. He agreed at once. I fastened 
a string to the wall on one side of the window ; it fell 
at first straight down, then passed along the floor between 
the curtain and where Eusapia sat, then went up to a pulley 
near the top of the wall on the other side of the window, 
and then to a place where the note-taker sat. The arrange- 
ment was that at a given signal the note-taker would pull 
in the string and if there was anything between the curtain 
and Eusapia it would be caught by the cord. The ar- 
rangement was not at all conspicuous unless you were 
close to it. This experiment proved a failure, for when 
we were assembled the next evening at the other end 
of the room before the lights were put out, Eusapia 
when she came in became very angry, went up to 
the curtain and pulled the string down. I have no 
satisfactory explanation of the way the curtain was 
moved, but I only saw it on one occasion and that 
for but two or three minutes, so that it is likely that I 



omitted to notice something which might have given 
the clue. 

It ought to be said that Sir Oliver Lcxlgc, Professor 
Richer and Dr. and Mrs Sidgwick observed Eusapia under 
mucli more favourable ('onditions at Professor Hichet’s 
house in an island near Hyercs, and that Sir Oliver is still 
of opinion that the effects observed there were genuine, 
and that the fliilure at (Cambridge later was due to her 
having lost most of her power in the meantime and 
supplanting it by conjuring. 'Hie phenomenon of the 
bulging-out of curtains without any apparent connection 
with Eusapia, and when there was no wind also, occurred 
on the island. The explanation favoured by Lodge is that 
she had the power of thrusting out a sort of supplementary 
arm, which has mechanical cjualities of pushing or pulling 
but which is not (')rdinary flesh and blood. This substance 
has been named ectoplasm. Lodge, on at least one occa- 
sion, thought he could see in the faint light a protuberance 
stretching out from Eusapia. It looked like a mere stump 
and not a hand. Within the last few years an Austrian 
medium, Rudi Schneider, has produced when iti a trance 
phenomena similar to Eusapia’s, including the bulging of 
curtains. Attempts have lxx*n made both in Paris and 
London to photograph the ectoplasm using the invisible 
infra-red rays, which can be used in the clarkened room 
where these phenomena are supposed to occur. These 
experiments, however, have not led to any conclusive 
results. In the experiment in Paris it was thought that 
the ectoplasm produced an appreciable absorption of the 
infra-red rays, but in those in London, where infra-red 
photographs were taken with an apparatus designed by 
Lord Rayleigh, no effects which could be ascribed to 
octeplasm were observed. I think that though physical 


instruments of very great delicacy have been used to detect 
physical effects produced by psychical means, they have 
as yet not given any evidence of their existence. Perhaps 
this is hardly to be wondered at. The people who claim 
to produce them are very psychic and impressionable, and 
it may be as unreasonable to expect them to produce 
their effects when surrounded by men of science armed 
with delicate instruments, as it would for a poet to be 
expected to produce a poem while in the presence of a 
Committee of the British Academy. 

Again, the delicate instruments used in physical 
laboratories may, until their technique has been mastered, 
give one result one day and a contradictory one the next, 
and illustrate the truth of Coutts Trotter’s saying that the 
law of the constancy of Nature was never learned in a 
physical laboratory. The most complicated physical ap- 
paratus is simphcity itself compared with a human being. 
I have described the only two cases in which anything 
happened that was claimed to be psychical. One of my 
most interesting experiences was a seance when nothing 
at all happened. Tliis was given in Mr Oscar Browning’s 
rooms in King’s College, Cambridge, near the end of last 
century by Madame Blavatsky, a very prominent theo- 
sophist of the time. She said at the beginning that her 
Mahatma in Tibet would precipitate a message, a cushion 
and a bell, and we sat waiting for, I should think, more 
than an hour, and nothing whatever arrived. The medium 
was not in the least abashed. She took the offensive, said 
it was all our fault, that our scepticism had created an 
atmosphere impenetrable to anything spiritual. She was 
a short and stout woman with an amazingly strong person- 
ahty, very able and an excellent speaker. So well did 
she speak that she convinced the great majority of the 



audience that the failure was their fault, and they went 
away thoroughly ashamed of themselves for having spoiled 
what would otherwise have been a most interesting 


Another branch of psychical research which may be 
connected with physics is that of thought-reading or 
telepathy, especiaUy that between people not far from 
each other. The first experiments pubhshed on this 
subject were made in 1884 on girls employed in a draper’s 
shop in Liverpool. These were tested in the physical 
laboratory at Liverpool University by Sir Oliver Lodge, 
and he satisfied himself that they, when blindfolded and 
when precautions were taken against the use of a code of 
signals, could describe, and in some cases give a rough 
copy, of a drawing made in sight of the rest of the audience 
and therefore presumably in their thoughts. Compared 
with other branches of psychical research, Httle has been 
done on this short-range thought transference between 
Hving people, though it was this which first suggested 
the idea. One reason for this is that this power of thought 
reading is exceedingly rare, very much rarer than was at 
first supposed. Another reason is that attention was at 
first directed to thought transference between the Hving 
and the dead, which raises much deeper and more im- 
portant questions. In my opinion the investigation of 
short-range thought transference is of the highest import- 
ance. It is quite possible, indeed very probable, that it 
may turn out to be of an entirely different character from 
the kind of thought transference that is supposed to occur 
in dreams or premonitions. This does not seem to be 



influenced by distance, whereas one would be very much 
surprised if that between living people did not decrease 
rapidly as the distance between them increased. I think 
it is now recognised that it is much more difEcult than 
was then thought to guard against the use of a code. The 
Zancigs, who were performing in London some years 
ago, did not, I believe, profess to possess any psychic 
power. Yet I saw them at a private house give, under 
most stringent conditions imposed on them by the present 
Lord Rayleigh (conditions which I expect were even 
more stringent than those imposed in the experiment of 
fifty years ago), an exhibition which, if they had professed 
to be thought readers, might have been held to establish 
the claim. 

There are other ways of communication between two 
people than by sight or audible sounds. There is such 
a thiug as inaudible sound. If the pitch of a musical note 
is raised above a certain point it ceases to be audible. The 
pitch at which this occurs varies from one person to 
another, and some people are able to hear notes of a pitch 
so high that they are quite inaudible to the vast majority 
of people. I once saw a very striking instance of this at 
the Cavendish Laboratory. A boy, who is now a dis- 
tinguished musician, came to the Laboratory to have the 
hmiting pitch he could hear tested by Galton’s whistle. 
This is a whistle whose pitch can be altered continuously 
through a wide range. He beat the instrument, for we 
could not produce a note of high enough pitch to be 
beyond his hearing. There were several people present, 
some of them young students — and the power of detecting 
high notes is much stronger in youth than in age — and 
none of them had heard anything for a long time before 
the whistle reached its highest note. Now if one of the 


parties in a performance like the Zancigs possessed this 
power to a quite exceptional extent, all that the other one 
would need to communicate with her by a code would 
be a very small whistle which could easily be concealed. 
The chances of anyone else hearing the signal would be 
small. I do not for a moment suggest that the Zancigs did 
the trick in this way. I have no idea how they did it. 

In my opinion by far the most important experiments 
of this kind were those made by Professor Gilbert Murray 
in 1916, In these there could be no question of the use of 
a code or of the good faith of any of the participants. 
An account of these is given by Mrs Sidgwick in Proceedings 
of the Society for Psychical Research^ vol. 34, p. 212. The 
participants in these experiments were either members of 
Professor Murray’s family or intimate friends. The ex- 
periments were made in private houses and not in a 
laboratory. This has the advantage that the thought 
reader was working under conditions much less formal 
and much more normal, and less likely to affect his powers, 
than if the experiments had been made in a laboratory.^ 
Professor Murray says the method followed is this : I go 
out of the room and of course out of earshot. Someone 
in the room thinks of a scene or an incident or anything 
she likes and says it aloud. It is written down and I am 
called. I come in, usually take my daughter’s hand, and 
then if I have luck, describe in detail what she has thought 
of. The least disturbance of our customary method, 
change of time or place, presence of strangers, con- 
troversy and especially noise is apt to make things go 

IS per^ps pertinent to remark that the original experiments in 
Liverpool, which were regarded as proving as well as suggesting the idea 
of thought transference, were made in a laboratory. 



Professor Murray himself does not believe that the 
results he gets are due to telepathy, if by that is meant 
the transmission of thought without aid from the ordinary 
senses, hearing, sight, touch, etc. As I understand him, 
he believes he gets into a state when he is peculiarly 
sensitive to noise, and his hearing becomes so acute that 
he hears something of the conversation between the 
“ thinkers ” when they are settling the subject they are 
to think about. It is not so acute, however, that he can 
distinguish the words they say, but he hears enough to 
suggest something to him. If it were a question of acute- 
ness of hearing alone a powerful microphone might be 
as effective as Professor Murray. The process is easier to 
describe, and the principle is the same, if we suppose the 
subject was chosen by writing instead of talking, and that 
the thought reader was in a condition when his sight was 
abnormally acute, though not sufficiently so to enable him 
to fix definitely what a particular word was. It might, 
however, be sufficient for him to see that only a few words 
would be consistent with what he had seen. If he had 
a quick imagination he might quickly grasp these possi- 
bihties and, beginning with one of them, if he found 
from observation of the thinkers that he was on the wrong 
track, start one of the others and go on until he got the 
right one. 

It is clear that if this were the process the percipient 
would have a much better chance of success if, as in this 
case, the thinkers were either members of his family or 
intimate friends with whose special interests in literature, 
history or politics, as well as incidents in their hves, he was 
well acquainted. 

The subjects selected by the thinkers seem to have 
been chosen at random, without reference to their suit- 


ability for distinguishing between the psychic explanation 
and the one favoured by Professor Murray. There are 
some of the experiments which seem, at first sight at any 
rate, to be inconsistent with his view, but it would be 
possible to find subjects which would test this view more 
severely than those actually used. 

Many efforts have been made to discover possessors 
of this power of short-distance telepathy, both in this 
country and in America, but they seem to be exceed- 
ingly rare. The case of Professor Murray shows, how- 
ever, that few though they may be, there are some, 
and it is in my opinion most important that the search 
for those should not be dropped. It is often asserted that 
telepathy has been conclusively proved. I cannot agree 
with this for the case of short-range telepathy. I think 
the utmost that can be claimed is the Scottish verdict — 
not proven. This does not mean that it has been shown 
not to exist. The subject is one of transcendent import - 
ance. I agree with the late Lord Rayleigh, who in his 
Presidential Address to the Society for Psychical Research, 
given very shortly before his death, said, ‘‘ To my mind 
telepathy with the dead would present comparatively little 
difficulty when it is admitted as regards the living. If 
the apparatus of the senses is not used in one case, why 
should it be needed in the other ? ” 


The phenomenon of water-dowsing, which borders on 
the occult, would seem at first sight one which could be 
more easily investigated than thought transference between 
living people. For there are a considerable number of 


people — ^in fact there is a Society of Dowsers — whose 
good faith is beyond question, who suffer a strange experi- 
ence when they walk over ground under which a stream 
of water is flowing. The most usual form of this is that 
when they hold a forked twig, generally a hazel one, with 
one branch of the fork in the right hand and the other in 
the left, the straight part is violently deflected when they 
are passing over running water. It seems necessary that 
the water should be underground, for few, if any, cases are 
recorded of this sensation being felt when crossing a bridge 
over a running stream. Some dowsers say that the twig 
will move when held by someone else provided they place 
their hands on his shoulders. There are some who can 
detect water without using the rod, since they experience 
pecuhar sensations when they are in places where the rod 
would move. The rod may be a convenient indicator of 
a physiological effect. There is no doubt of the reality 
of the dowsing effect. In fact, in many agricultural dis- 
tricts the dowser is the man they call in when they want to 
find the right place to dig a well, and he very often suc- 
ceeds. We had an example of this at Trinity College. 
The water supply to one of our farms was very defective 
and a new well badly wanted. At first the Senior Bursar, 
who was a Fellow of the Royal Society, proceeded in the 
orthodox way and employed eminent geologists to report 
on where we ought to sink a well. Their advice, however, 
did not lead to the discovery of any water. Our land agent 
said, ‘‘ If I were you, I would try old X, who has found a 
good many wells in this county and who will sink the well 
on the terms ‘ no water, no pay ’ As there seemed 
nothing else to be done, the Bursar employed him and he 
found water. For this we were assailed in an article in 
Nature, which lamented that Trinity College— the College 


of Newton — should have given countenance to such super- 
stitious and unscientific practices. 

Although I think most of the people who have paid any 
attention to the subject beheve in the reality of dowsing, 
there is no agreement about its cause. 

The common-sense view would be that, since under- 
ground water would produce some effect on the vegeta- 
tion on the surface above it, a man who had good powers 
of observation and long experience, might be able to detect 
water by small differences in the herbage which would 
escape the notice of the ordinary observer, and that the 
movement of the rod came after the discovery and not 
before. This was the method of the Abbe Paramelle, a 
most successful discoverer of springs, who claims that in 
the twenty-five years between 1829 and 1 8 54 he had located 
more than 10,000 springs ; and that between 8000 and 9000 
wells had been dug of which over 95 per cent were success- 
ful. He did not use the divining-rod and spent all his 
time, except on Sundays, looking for water. This may be 
the method in some cases but it certainly is not so in all. 
In some cases the movements of the rod occur when the 
dowser has been blindfolded, or when he has not been near 
the part of the country before. In this connection it may 
be pertinent to say that in the early days of radio-activity 
at the beginning of this century, I examined specimens of 
water freshly drawn from a good many wells in different 
parts of England and found that they all, though in very 
different degrees, contained the radio-active emanation 
from radium. This only retains its activity for four days, 
so foat if the water were stagnant it would soon lose its 
radio-activity. Thus, if this were connected with the effect 
produced on the dowser, it would explain why it is that 
he can only detect running water. If inhaling a small 


quantity of radium emanation produced in the dowser 
rigors such as are produced by some drugs, his fingers 
when over the water might close with a convulsive clutch 
on the forks of the twig and require a large force to keep 
the rod in position. I must, however, confess that though 
I have often inhaled the emanation I have never observed 
that it produced the slightest effect upon me ; but I am 
not a dowser. 

One amusing thing about the tests of the waters from 
these wells was that by far the most radio-active was that 
from a well-known brewery. When I reported this to 
them I at once received instructions that I was not on any 
account to pubhsh it, for if I did nobody would ever 
buy their beer. When I told this to an American friend 
he said it illustrated the difference between the business 
methods in the two countries, for if it had been an Ameri- 
can brewery, the whole country would have been placarded 
with advertisements— “ Drink Smith’s Radio Beer 

The early history of the “ divining-rod ” does not 
inspire us with much confidence. Its first appHcations 
were to the detection of criminals, metals and lost treasure 
and not to the discovery of water. Aymar, a French 
dowser, created a great sensation in 1692 by tracking down 
by the divining-rod the murderer of a man and his wife. 
He claimed that when he placed his foot on anything 
which had been touched by the criminal the rod moved, 
his temperature rose, his heart beat more rapidly and he 
felt faint. These sensations were only produced by mur- 
derers , thieves, metals, or water left him unmoved. 
The divining-rod was used to discover metals in Germany 
(Dousterswivel in The Antiquary was a German), Austria 
and Cornwall. In this country attention has been mainly 
concentrated on water-divinmg, though some of the most 



successful water-diviners have claimed to be able to detect 
metals as well. Thus it is stated that John Mullins, a 
very celebrated water-diviner and well-sinker, when a 
sovereign had been placed under each of three stones 
in a row of ten in a road, passed his rod over the stones. 
When he came to a stone and the rod did not move 
he said, Nothing here but if it did move, he 
lifted the stone, took the sovereign and said, “ Thankee, 
Master This is an experiment that could easily be tried. 
There are some dowsers who claim to be able not merely 
to detect metals but to be able to tell what the metal is. 
The most unexpected apphcation of the divining-rod I 
have come across is a medical one. I have met a dowser 
who told me that, before taking a bottle of medicine, he 
passed the rod over it and if the rod were deflected he knew 
the medicine would do him good and he took it, while 
if the rod were not deflected he knew the medicine would 
be of no use for his complaint. 

The greater number of experiments with the divining- 
rod have been made for the purpose of obtainmg water and 
not for discovering the way in which the effects of the rod 
are produced. The object has been commercial rather 
than scientific. 

In Barrett’s Divining Rod, p. 256, an account is made of 
an experiment made to detect hidden coins by the divining- 
rod, which was successful, though there were one or two 
incidents which might arouse suspicion. 

The divining-rod is perhaps of all phenomena which 
may be thought to be psychical, the one most favourable 
for experiment. The motion of the rod is a mechanical 
eSect and gives an indication of the magnitude of the 
phenomenon. The conditions under which the effect 
occurs can be made definite, and there is no lack of 


trustworthy people who possess the dowsing power : 
for these reasons I think such experiments are well worth 
making d 

^ Since the above was written, I have seen a paper by Mr H. M. 
BuJgett, published by the British Society of Dowsers, on the connection 
between effects on a divining rod and the readings of an instrument 
designed to detect very penetrating radiation. There seemed to be 
indications of some connection, but these were very faint. It would be 
interesting to see if the dowser could, by his divining, detect a strong 
beam of penetrating y rays. 



First and Second Visits to America. 1896, 1903. 

I N the autumn of 1896 my wife and I went to America 
to attend the celebration of the Sesquicentenary of 
Princeton University, at which I was to give a course of 
lectures on the Conduction of Electricity through Gases. 
We crossed in the Campania, then quite a new boat. 
When we reached New York there was some difficulty 
in getting our baggage through the customs. I had a 
suitcase full of congratulatory addresses from various uni- 
versities and scientific societies in England. Each of these 
was in a cardboard cylinder. There had been some rioting 
and bomb-throwing about this time in America and the 
inspector at the Customs at once suspected bombs. He 
asked me what these cylinders were, and I said they con- 
tained addresses to Princeton University. He then asked 
why I was taking them. I said it was for their Sesqui- 
centenary. ‘‘ Oh ! he said, “ I see, you’re a foreigner. 
But where’s Princeton anyhow ? ” I said it was quite 
close to New York. He said he had never heard of such a 
place, and appealed to another inspector, who said he had 
not either. He refused to let my baggage through. I then 
demanded to be taken to the head man. After some more 
talking he consented, and took me to his office. Very 
fortunately he turned out to be a Princeton man, who 
received me with enthusiasm when he knew my errand 
and was not at all pleased with his subordinates for what 
seemed to him incredible ignorance. 



The morning after our arrival we went to Baltimore 
to stay with some great friends of ours who Uved there. 
We were fortunate enough to arrive just in time for me to 
see the final round in a great baseball competition. One 
of my illusions was soon dispelled. I had always thought 
Americans as a race would show the characteristics of their 
ancestors who came over in the Mayflower ^ would be grave, 
undemonstrative, and would take their pleasures sadly. 
But though I was in one of the best places and surrounded 
by the most prominent men in the city — lawyers, bankers, 
doctors, professors and even clergymen — the game had 
only been going on for a few minutes when most of these 
were shouting at the top of their voices ; some of them 
shouted so much that they lost the power of articulation 
and could only croak. I always myself get very much 
excited by a keen contest and feel for the moment that 
nothing on earth matters so much as that the side I am 
interested in should win, and probably if I had wished 
very much that one of the sides should beat the other and 
had understood the finer points of the game, I should have 
done as they did, I enjoyed the match thoroughly. I had 
never seen baseball before and it is a great game. The 
idea is the same as that of the English game of rounders in 
that the batsman, armed with a broomstick, tries to hit 
the ball so far that he has time to run to a base before a 
fieldsman can gather the ball, throw it at him and hit 
him ; but there is as much difference between this and a 
good baseball match as between cricket played by boys in 
a side street with three white lines on a waU for the wicket, 
and the match between Gendemen and Players at Lord’s. 
The fielding, /.e. the throwing and catching of a first-class 
baseball team, is superb and reaches a standard but rarely 
attained in English cricket. The pitcher, who corre- 


spends to the bowler at cricket, throws, not bowls, the ball 
full pitch at the batsman, and by putting spin on the ball 
can make it swerve in the air either to the right or to the 
left, or up or down. This interests the physicist as well as 
the sportsman, for it is a striking illustration of the hydro- 
dynamical principle that a ball moving through air always 
tends to foUow its nose, the nose being the point on the 
ball which is in front. Thus if a ball is moving hori- 
zontally in the direction of the arrow, the foremost point on 
the ball will be N, the point right in front of the centre C. 
If the ball is not spinning, this point, like every other part 

of the ball, is moving horizontally, and the ball, following 
its nose, will do so too. But suppose the ball is sp inning as 
in the figure, about an axis at right angles to the plane of the 
paper, N, in consequence of the spin, will be moving down- 
wards (this spinis.what is called top spin in lawn tennis) 
and the ball will tend to follow it and will therefore dip ; 
if the spin were in the opposite direction, the nose would 
be movmg upwards so that the baU would tend to soar. 
If the axis of spin were vertical instead of horizontal 
the nose N would have a sideways motion and the ball 
would swerve either to right or left. If the axis of the 
spin were not truly vertical or horizontal, the ball would 
both swerve and dip or rise. 

We saw Baltimore under exceptionally favourable 
OTcumstances, for our host was a professor in Johns Hop- 
kins University, and both he and his wife belonged to old 



Baltimore families. We thus saw much both of academic 
society and also of that representing the old social life of 
Maryland. I have never been in a city where the hospi- 
tahty was more charming, more generous or more intimate 
than that of Baltimore. Everyone seemed to know every- 
body else and to call him by his Christian name, and gener- 
ally omit the other. The result was that I knew the 
Christian names of a great many people but very few of 
their surnames. This was especially the case at the Mary- 
land Club, known all over the world for the excellence of 
its cooking ; indeed it has been called the “ gastronomic 
centre ” of the universe, and certainly I have never been in 
one where the cooking and the food were better. The 
standard of cooking in private houses is also very high. 
It is here that you get that excellent dish, Maryland 
chicken, at its best. 

The country round Baltimore is the epicure’s paradise. 
The shores of the Chesapeake Bay supply abundance of 
oysters of many kinds. In a restaurant at which I had 
lunch, two pages of the bill of fare were occupied by the 
names of different kinds, some of these as large as those 
which Thackeray ate when he was in America, and which 
he said made him feel that he was eating a baby. The Bay 
too, is the home of the celebrated dehcacy, the canvas-back 
duck, which plucks the celery from the bottom of the 
marshes while another duck, the red head, waits until the 
canvas-back comes to the surface and tries to rob him of 
the celery. This dishonesty seems to affect the flavour, 
for though the ducks are much alike and eat the same food, 

I have heard a Baltimorian, when he wished to describe 
adequately the monstrous stupidity of someone under 
discussion, say that he was so stupid that he could not tell 
the difference between a canvas-back and a red head. 



I should think Baltimore must be a paradise for young 
girls, for the debutantes ”, i.e. the girls who have ‘‘ come 
out ” not more than a year ago, are the Queens of Society. 
It was for them most of the parties seemed to be given. 
Their parents placed the drawing-rooms at their disposal 
to entertain any guests they hked. For one year they reign, 
then they make way for the next crop. 

Our hosts had a most deHghtful example of the old 
negro servant who had been in the family for many years, 
even before the hberation of the slaves. He took a keen 
personal interest in the guests, would advise them about 
what they should do and where they should go and 
whispered at dinner the wine he would recommend. His 
manners were so good that all this seemed quite natural 
and very agreeable. He had refused to leave when he had 
been liberated after the Civil War, saying that he had no 
opinion of free niggers. It takes some time before an 
Enghshman gets to realise the feeling of Americans towards 
the coloured people. I was helped by the following in- 
cident. A kindly old gentleman was talking about Booker 
Washington, the coloured statesman who did wonders for 
the improvement of his race. He said, “ I have always 
been accustomed to call a coloured man ‘ Uncle but I 
felt it could not be right to call such a great man that. 
I could not bring myself to call any coloured man ‘ Mister 
and I did not know what to do. At last I had a bright idea, 
and I called him ‘ Professor 

Johns Hopkins University in Baltimore was, I beheve, 
the first umversity to be founded where the primary con- 
sideration was research and not teaching. There were at 
first no undergraduates — the students had already gradu- 
ated at some other university. The first President was 
Professor Gilman, and he had the very difficult task of 



selecting a staff of Professors suitable for this purpose. 
Among the earher Professors were Henry Rowland, the 
great spectroscopist, whose investigations with diffraction 
gratings made in Johns Hopkins laboratory started a new 
era in spectroscopy ; he spent most of the later years of 
his hfe in inventing and developing a printing telegraph, 
one which, like many now in use, would print the message 
as it was received (in this he was before his time and I am 
afraid did not gain much by it) ; Ira Remsen, Professor of 
Chemistry, who later became President ; G. L. Gildersleeve, 
Professor of Greek. 

Among the early students was Woodrow Wilson, 
subsequently President of the United States, who studied 
history for a year. 

The new university had to fight against several dis- 
advantages. Johns Hopkins had not been a popular 
citizen and people were reluctant to give money to a 
university called after him : again, most of the professors 
and students were northerners while Baltimore was dis- 
tinctly southern, and in 1876 the feeling aroused by the 
war was still strong enough to make them unpopular. 
Indeed, though Johns Hopkins has been the pioneer of the 
“ Research University ” not only in the United States but 
in the world, it has never received, as it deserved to receive, 
benefactions comparable with those received by some 
other American universities. It now, I believe, does admit 
undergraduates, and by the aid of the State has been able 
to obtain adequate buildings on a fine site. I believe that 
when Johns Hopkins University first applied to the State 
for a grant, their representative (a Professor) had to go 
before a committee of town councillors. One town 
councillor was very anxious to find out how many hours 
a day a Professor spent in teaching, and asked the Professor 


this question. The Professor said it was a difficult question 
to answer, there were so many things to be taken into 
consideration. He was asked, “ Does it take four hours 
a day ? ” He said, ‘‘ Perhaps about that “ What do 
you do the rest of the day ? ’’ he was asked. “ Well,” he 
said, “ some time was taken up in the preparation of his 
lectures.” “ What 1 do you mean to say you do not 
know your lessons yet ? If one of our school marms did 
not know her lessons, we should soon get rid of her.” 

The preparations for the Presidential Election were in 
full swing when we were in Baltimore. It turned on the 
question of bimetaUism and excited a quite exceptional 
amount of interest. The bimetaUic candidate was Bryan, 
who was thought to have owed his nomination to his 
phrase “ Thou shalt not crucify humanity on a cross of 
gold ”, which ran like wildfire through the country. 
McKinley was the other candidate, and he supported the 
maintenance of the gold standard. I never knew an 
election excite such bitter feelings. The language of some 
highly respectable people gave one the impression that, if 
they could have killed Bryan without any danger of being 
found out, they would have done so without a moment’s 

After a most pleasant but too short stay in Baltimore 
we went on to Princeton for the dehvery of my lectures, 
staying with Professor and Mrs Fine. Fine was the 
Professor of Mathematics and was a great friend of 
Woodrow Wilson, who, after he became President, 
wished to make him American Ambassador to Berlin. 
Fine, however, had to refuse it on account of the expense 
it would have entailed. 

My lectures were very well attended and I was able to 
meet many of my audience under conditions more favour- 


able for social intercourse than lectures. Princeton, of all 
the American universities I have visited, is the one most 
reminiscent of Cambridge. It is not surrounded by work- 
shops or shops, but by spacious lawns studded with fine 
trees which recall the Cambridge “ backs To a Trinity 
man, especially, it recalls Cambridge, for the gateway to 
one of the courts is copied from the Great Gate at Trinity. 
When I last visited Princeton after an interval of more than 
twenty years I found the resemblance still greater, for they 
had erected a beautiful building for the post-graduate 
school. I had the pleasure of dining there one evening, and, 
just as in Trinity, we dined in gowns and had a Latin 
grace, and if I remember correctly, port after dinner. The 
dinner was the more agreeable since Dean West, to whose 
exertions the school is mainly due, was in the chair. 

The houses of many University Clubs along Prospect 
Avenue are a very interesting feature of Princeton. They 
are very attractive buildings and luxuriously furnished, 
though I was told that they were so well endowed through 
the munificence of ' old members that the charges to the 
undergraduate members were not extravagant. Those 
Clubs have played an important part in American history, 
for it was owing to them that Woodrow Wilson became 
President of the United States. It came about in this way : 
to be or have been a member of some of the Clubs gave 
a man considerable social distinction, not only among his 
fellow undergraduates when he was at Princeton, but also 
for the rest of his life in most of the eastern States. The 
result was that some of the undergraduates thought that 
the most important thing they could do at Princeton was 
to “ make i.e, get elected to, a good Club hke, say, 
Ivy They could not be elected until the end of their 
second year, so that their first two years were devoted to 


doing the things which they thought would best promote 
their election : unfortunately they believed that it was 
fatal to their chances if they did any work. This clearly 
called for reform, and Woodrow "Wilson, when he was 
made President of Princeton in 1906, set to work to 
remedy it. He began by raising the standard required 
for entrance to the University, and supplemented the 
lectures of the Professors by the appointment of pre- 
ceptors, w^ho give individual attention to the students. 
Mere attendance at lectures is a very unsatisfactory method 
of teaching for any but the best student. The ordinary 
student needs someone who will explain his difiiculties, 
set him essays and discuss them with him. This, which 
is the system employed in Cambridge Colleges, was to be 
the work of the preceptors. They would be constantly 
in touch with the undergraduates and could soon jBnd out 
if they were not working. These, however, were only 
preliminaries to a much more fundamental scheme which 
Wilson had drawn up after consultation with the Pro- 
fessors at Princeton. On this scheme the Clubs were to 
be aboHshed and replaced by a number of Colleges, bearing 
to the University much the same relation as the Colleges 
at Oxford and Cambridge bear to those universities.^ 
The Colleges were to be places where the undergraduates 
Hved and had their meals. Each College was to have its 
own Master and staff of preceptors, and was to be an in- 
dependent unit. Each undergraduate was to be a member 
of a College and Hve in it, and the members of a College 
were to have all their meals together, and to make this 
possible for the poorer students, these were to be of a very 
simple character. In American universities there are few, 

* Tliis system has since been introduced with success into Harvard 



if any, scholarships for undergraduates, so that these, if 
they are not supported by their parents, have to earn enough 
themselves to enable them to stay at the university. A 
considerable number did this by acting as waiters in 
summer hotels, tram conductors during rush hours, de- 
Hvering the morning newspapers and so on. This all 
takes time and work and those who had to do it were 
seriously hampered in their studies. To reduce the neces- 
sity for this extra work it is very important to keep uni- 
versity expenses down as much as possible, and life in 
Woodrow Wilson’s Colleges would necessarily be austere 
and a great contrast to that which had prevailed in their 
Clubs. In Oxford and Cambridge the problem of the 
poor student is solved by granting scholarships to under- 
graduates who have shown ability. There are a great 
number of these scholarships. For example, the Cam- 
bridge Colleges in 1934-35 granted from their own funds 
scholarships amounting in value to about 5 6,000. In 
addition to this, scholarships are awarded by some of the 
great City Companies and by the educational committees 
of the County Councils. In this way not a few under- 
graduates receive from scholarships an income sufficient 
to support them at Cambridge in a style which enables 
them to join fully in the social hfe of the place, to meet 
men of very different means, experience and opinions, to 
discover that a man may hold views which you regard as 
pestilential and yet be a very good feUow ; to get, in 
fine, a wide knowledge of men and manners which will 
be of great service to them in after life. 

There is a very great deal to be said in favour of this 
method, but it was not at the time possible at Princeton. 
Feehng in America regarded holding a scholarship as a loss 
of independence. It admired the grit and determination 



of the man who refused to accept money when he could 
earn it some way or another himself. The scholarship 
system seems contrary to the American spirit. Up to the 
time when he made these proposals Wilson’s success at 
Princeton had been unprecedented. He was liked by 
many and admired by all. He had the ear of the Trustees, 
who appointed a Committee to consider his scheme and 
report to them. They reported in favour of the scheme, 
and in June 1907 all but one of the Trustees voted for 
accepting the Report. It was not long, however, before 
opposition arose. This came chiefly from the older 
Princeton men who had been members of the Clubs. 
This was only natural ; the Clubs were the places where 
they had made their most intimate friends ; their most 
vivid and pleasant recollections of Princeton were asso- 
ciated with them. Of their attachment to and interest in 
Princeton there could be no doubt. They had found the 
funds for many beautiful buildings, and year after year had 
made up the deficit between income and expenditure. 

There was at this time another question before the 
University which made the situation still more difficult. 
Dean West, a man much beloved by many old Princeton 
men, had started, some time before, the idea of having a 
residential College at Princeton for graduates who were 
engaged in study or research. The President favoured 
this idea, but thought it essential for the unity of the 
University that this College should be on the campus 
close to the other University buildings. Dean West was 
untiring in his efforts to raise funds for this College and 
a bequest of $ 500,000 was received on the condition that 
the College should not be on the campus. The President’s 
influence at this time was so great fliat this bequest was 



The fight grew very fierce and, in its later stages, bitter. 
The President was adamant : he would not make the 
slightest concession. This attitude is certainly not diplo- 
matic and, moreover, not likely to be successful. The 
result of the poHcy all or nothing is much more likely to 
be nothing than all, and so it was in this case. Another 
bequest for the graduates’ College, this time for $2,000,000, 
coupled again with the condition that it should not be on 
the campus, was accepted by the Trustees, who thought 
that with such an endowment the College, though it 
might not be in the best place, could yet be made useful 
to the University. Wilson’s scheme came before the 
Trustees again in October, and whereas six months before 
only one had voted against it, now only one was for it. 
The scheme was dead and the Clubs are still flourishing. 

This defeat made his position as President intolerable, 
and he soon after accepted nomination for the Governor- 
ship of New Jersey. He was elected Governor of New 
Jersey in 1911 and in 1913 President of the United States. 

This is a very interesting case. If he had been a diplo- 
mat he could probably, with the prestige and goodwill 
he possessed, have been able to carry a scheme which, 
though not all he had asked for, would have been suffi- 
ciently near it to make him think it would be worth a 
trial, and would have occupied his attention and kept him 
at Princeton for several years, and he would certainly not 
have been President during the Great War. 

His career was a great tragedy. The last time I ever 
saw him was at a Levee at Buclingham Palace in 1919, 
when he was on his way to the Peace Conference. He was 
standing next to the King, and the guests filed before him 
and were presented to him. It seemed then possible, and 
some thought it probable, that he might in a short time 


be in a position to exert greater influence over the affairs 
of the world than any man ever had ; yet twelve months 
after he had lost his influence even in his own country. It 
was not the failure to secure the Treaty he proposed that 
was most significant. That Treaty seemed to ignore the 
fact that there had been a war, that for four years France 
and England had been suffering without intermission un- 
paralleled losses of men and money, bitter grief and great 
distress, that France had been invaded and a large part 
of it laid desolate. Could it be expected that, with these 
bitter experiences fresh in their minds, France and England 
could proceed to discuss the Treaty as if they had not 
occurred, to put them out of their minds and consider only 
what would be best for Europe in the distant future ? Far 
more significant, I think, is his failure to bring America into 
the League of Nations. Some think that he could have done 
so if he had stayed in America, or if he had brought with 
him to Europe prominent members of the different parties : 
there were even some, among them Mr Arthur Balfour, 
who thought that, though he failed at the first attempt, he 
might ultimately have succeeded if his health had not 
broken down, for though he could not manage the Senate, 
few men have had his power of enlisting the people. Be 
these things as they may, the questioffarises, Might it not 
have been a good thing for the world if Wilson had 
succeeded, and is it not possible that in the future he may 
be greatly honoured as one who pointed out the right way 
though he could not persuade otiiers to follow it ? 

One of the most interesting of my experiences was 
a visit to the Military Academy at West Point, the 
place where officers are trained for the American Army. 
I never had much belief in theories of education, but this 


shattered such as I had. In the iEirst place, the State pays 
all their expenses and does not allow the students to have 
the control of any money : if they wanted a postage stamp 
for a letter they had, I was told, to go to the office and get 
it from there. After entering West Point they remain 
there without a break for nearly two years. To mitigate 
this isolation the Government provides a Guest House at 
which friends and relations of the students may stay at 
the week-end, when generally there are dances. The 
students have to attend a great many classes, but these 
are interspersed with riding, games and gymnastics, so 
that they certainly did not show any of the usual symptoms 
of over-study, but were a remarkably vigorous, weU-set- 
up body of men. 

I went to one of their classes ; there was a belt of 
blackboards round the room ; in front of them, the cadets 
were standing at attention : the subject was mechanics. 
The instructor asked me if I would take the class, but 
naturally I asked to be excused. He then called on one of 
the cadets and told him to prove the formula giving the 
time of swing of the simple pendulum. He began, “ I 
am requested to ... ” but he got no further, for the 
instructor rapped on the table with his gavel and said, 
“ You’re nothing of the kind, you are ordered — go on 
He went on and repeated absolutely verbatim the proof 
given in the textbook ; even the lettering on the figure 
was the same. This method of learning by rote seems 
contrary to any reasonable theory of education, but the 
irony of it is that it produces excellent results. So much 
so that there is a great demand for West Point men by 
large employers of industry throughout the country, and 
there is great difficulty in holding them for the army. The 
fact is that discipline is the keynote of the system. The 

177 N 


students are experts in discipline, a very important thing 
where large bodies of men are employed. 

We returned from West Point to Princeton in time for 
the official proceedings of the Sesquicentenary. These 
lasted for three days and were brilhantly successful, the 
result of hard work for many months, magnificent organ- 
isation and the enthusiasm and generosity of Princeton 
graduates. The celebration was more than that of the 
Sesquicentenary of the old Princeton, which was not 
officially the University of Princeton but the College of 
New Jersey ; it was that of the birth of the new Univer- 
sity of Princeton, A large banner with Ave Vale 
Collegium Neocaesariense ” on one side, and “ Ave Salve 
Universitas Princetoniensis ” on the other, hung over one 
of the arches, and there were innumerable flags showing 
the Princeton colours, orange and black. The weather was 
magnificent, and the tuHp trees in the campus glowed in 
the orange of Princeton. It was rumoured that Mr Bur- 
bank, a great American gardener who seemed to be able 
to produce any kind of flower or fiuit to order, had been 
commissioned to produce a chrysanthemum vrith both 
the Princeton colours, orange and black, but had not had 
quite time enough to get it just right. 

The proceedings of the first day began with a sermon 
in the morning fiom the President of Princeton University, 
Dr. Patton. In the afternoon there was an address wel- 
coming the delegates firom other universities, given by the 
Rev. Howard Duffren, while President Ehot offered the 
congratulations of the American universities and learned 
societies, and I did the same for the European. 

The second day began with the recitation of the 
Academic Ode by Dr. Henry van Dyke representing the 
CUo Debating Society, while the oration was delivered by 


Professor Woodrow Wilson representing the rival debating 
society, the American Whig Society. Woodrow Wilson’s 
theme was “ Princeton in the National Service He 
mamtaitied that by far the most important thing for Prince- 
ton to do was to give the kind of education best adapted 
for making them good citizens. “ It should be a place 
where to learn the truth about the past and hold debates 
about the affairs of the present.” The oration, which was 
dehvered with great dignity and with excellent elocution, 
roused the audience to the highest pitch of enthusiasm. 

In the afternoon there was a football match between 
Princeton and the University of Virginia. It was my first 
introduction to American football and I enjoyed it very 
heartily- I have attempted on page 189 to give some 
account of the American game. 

The day closed with a torchhght procession over a 
mile long which the President of the United States and 
his wife, Mrs Cleveland, came to see. A year had been 
spent in organising it. It was headed by a corps dressed 
in the uniform of the “ Mercer Blues ”, the Princeton 
regiment that fought in the Civil War. Their leader 
tamed the sword General Hugh Mercer had worn at the 
tattle of Princeton, and was followed by representatives 
tf sixty “classes”, beginning with the class of 1839. 
rhere were lanterns and torches of almost every colour, 
tut orange, the Princeton colour, overtopped them all, 
he others looking hke specks of colour on an orange 

The morning of the third day was spent in conferring 
ifty-six honorary degrees. On the recipients and the 
lelegates were to be seen the gowns of almost every uni- 
versity and academy, along with some of a type that had 
Lever been seen before. It was, I beheve, the first time that 


doctors’ robes had been worn in America, and two at least 
of the American Professors had, with characteristic thirst for 
improvement, borrowed, from President Gilman of Johns 
Hopkins, gowns which he had brought home from Europe, 
where he had received doctors’ degrees from several univer- 
sities. They took these to their wives’ dressmaker and 
told her to select the best features of each and produce 
something styHsh. The result was remarkable : they were 
the only doctors’ gowms I ever saw that had anything that 
could be called a good fit. These, however, went in at 
the waist and then billowed out into something very like 
a shirt in a very coquettish and most unacademical fashion. 
The President of the United States made a speech after the 
conferment of the degrees. 

On Friday the delegates left Princeton, and many of 
them attended in the evening a dinner given by the Uni- 
versity Club of New York. It was my good fortune to 
sit next a very celebrated New York physician, and when 
he heard that I was going to sail for England the next day, 
he asked if I was a good sailor. I said so far I had not 
suffered from sea-sickness. He said, I was just going to 
say that I was sorry to hear it, but that is not quite what I 
meant. I meant that I was sorry that I could not be of 
service to you, for I have a remedy for sea-sickness,” I 
said I should be very glad to know what it was, for one 
never knew what might happen. “Well,” he said, “ as 
soon as you get setded on board have a Manhattan cocktail 
and then slowly nibble dry biscuits. As soon as you feel 
it an effort to do this, take another cocktail and then begiu 
again at the biscuits and so on. The theory of it is that you 
will be aU right as long as you can take die biscuits ; the 
cocktails are to make you want to do this.” I have never 
had occasion to test the remedy but I mention it because it 


sounds less disagreeable than any I have heard of. My 
wife and I sailed next day in the Lucania and, after an 
uneventful passage, arrived at Cambridge in time for the 
October Term. 

Princeton University has developed greatly since the 
Sesquicentenary : it has now large and well-equipped 
laboratories in all the main branches of experimental and 
biological science. It has been able to attract Professors 
of great distinction, some of them, I am proud to say, old 
pupils of my own. It has been the source of many im- 
portant discoveries, and has flourishing schools of research 
in many branches of science. It has lately received a muni- 
ficent endowment of research from Mr Louis Bamberger 
and his sister Mrs Fuld, who have made an initial gift of 
$5,000,000 to enable students who have received the Ph.D. 
degree or its equivalent to continue their independent 
training and to carry on research with adequate support, 
without pressure of numbers or routine, and unharried by 
the need of obtaining practical results. A school for 
research in mathematics was estabhshed in 1933 with a 
staff of very distinguished Professors : it has already 
attracted a considerable number of students, some of 
them from Trinity College. 

Second Visit to America 

My next visit to the United States was in the spring 
of 1903 when I went to give the first course of lectures 
under the SiUiman Foundation. The lectures were on 
“Electricity and Matter” and were subsequently pub- 
hshed as a book with that title by Scribners. 

Yale University is at New Haven, the most populous 


city in the State of Connecticut. It was often called the 
“ Elm City ” from the number of avenues of elms which 
lined the principal streets. These at the time of my visit 
were a prominent and very pleasing feature of the town : 
shortly afterwards they were for a time destroyed through 
the ravages of the elm disease. It was my good fortune 
to be, throughout my visit, the guest of the very pleasant 
“ Graduates’ Club The Club House was in the Uni- 
versity and was frequented by many of its teachers. From 
informal talks with them I got a more intimate idea of the 
University than I could have done if I had Hved outside. 
While I was in New Haven, both the town and Univer- 
sity were much excited and disturbed by a situation which 
had arisen through a strike of the tramcar drivers. To 
avoid inconvenience to the pubhc some of the students 
had volunteered to act as drivers during the rush hours. 
The tramwaymen protested against this and demanded that 
the President of the University should forbid it. He 
refused to do so and party feeling ran very high, higher 
than I have ever known in an Enghsh strike. Shots were 
fired and, as far as I could see, there was httle or no 
sympathy between the men and their employers. The 
change which has occurred in this respect is very remark- 
able. On my last visit to America I found all the great 
manufacturing companies competing with each other in the 
amenities they offered to their employees. The first 
things you must see when you visited their works were 
the playing-fields, the recreation hall, the club-houses. 
They told you of the weekly dances and dramatic per- 
formances, and positively gloated over the amount the 
company had spent on these. They were evidendy bent 
on trying to kill sociahsm by kindness. 

Besides the trouble about the strike, there was an out- 

SIR J. J. THOMSON : igo2 

Ironi the painting li) Arthur Hackei' in th<' (lu\endish Laboratory 


break of typhoid fever in the town and an attack in the 
newspapers on the water company for not having taken 
greater precautions to prevent infection spreading from a 
cottage on the gathering-ground, where there was said 
to be a case of typhoid. The manager of the water 
company was in the Club one evening and said that a man 
had come to him that afternoon and asked him if he would 
like to have positive proof that the infection had not come 
that way. The manager said that was just what he 
wanted ; he said the company would certainly give a 
hberal reward, but what was the proof ? The man said 
he had been up to the cottage, and there certainly was a 
stream which ran near it and then into the reservoir ; 
that looked bad, but he had followed the stream and 
found, before it got to the reservoir, a waterfall of some 
six feet or so. This, he said, proved that the cottage 
could not have been the source of contagion, for no 
microbe could possibly have fallen down it without 
breaking its blooming neck. 

Yale University is one of the oldest in America, having 
been founded in 1701 when it was connected with the Con- 
gregationalist Church, just as Princeton was with the 
Presbyterian and Harvard with the Unitarian. It is now, 
like them, undenominational. 

Most of the science teaching when I was there was 
given in the Sheffield School of Science, which is at 
some distance from the other part of the University. 
The students’ Clubs, as at Princeton, play a very 
important part in the hfe of the undergraduates, and 
to be elected to ‘‘ SkuU and Bones ” is regarded as the 
greatest distinction they can attain. I did not, however, 
hear from the Professors any complaint about its effect 
on their studies. The mode of election is Spartan. On 


Commemoration Day, when many relatives and friends 
of the undergraduates come to New Haven, at one stage 
of the proceedings when the undergraduates and the guests 
are out on the campus, the secretary of the Club appears, 
mixes with the crowd and taps one man after another 
on the shoulder. These are the selected candidates and they 
leave the crowd and go into the Club House. This is all 
very pleasant for them, but it is a bitter experience for those 
who hoped and expected to be elected to have their failure 
announced in so public a fashion and on such an occasion. 
I was told of one case when a boy who had been thought 
by most people, as well as by himself, as certain of election, 
was so affected by his failure that he committed suicide the 
same day. 

C The rivalry between Yale and Harvard is quite as keen 
as that between Cambridge and Oxford and shows itself 
in more unconventional ways. I saw at the house of one 
of the Professors a dog who had been trained to pretend 
to be sick whenever he heard the name Harvard . ) 

There is a distinct difference in “ tone between Yale 
and Harvard. As might be expected from its proximity 
to Boston, which was for long the most important literary 
centre in the States, the atmosphere of Harvard is more pro- 
nouncedly literary than that of Yale. President Ehot, 
who was for many years President of Harvard, was for 
nearly the whole of that time the leading authority on 
education in the States, and was a man whose opinion on 
very many subjects carried great weight in the country. 
Harvard was thus very much in the pubHc eye on educa- 
tional and Hterary subjects and this was not without its 
effects on the undergraduates. 

On the other hand, Yale had in Willard Gibbs one of 
the very greatest mathematical physicists of his generation. 



He was bom in New Haven : his father was a professor at 
Yale. He himself was first a student, then a Tutor, and, 
from 1871 to his death in 1903, a Professor in that univer- 
sity. I do not know of any case of a more intimate 
connection between a man and a university. It was 
long, however, before his university recognised that 
he was a great man. He had not been a success as a 
teacher of elementary students. Indeed it is said that there 
was at one time a movement to replace him. A prophet 
is, however, not without honour save in his own country, 
and Clerk Maxwell in 1876 called attention to the vital 
importance of Gibbs* work. Maxwell was so impressed 
with it that he constructed with his own hands a model of 
Gibbs* thermodynamic surface and sent a copy of it to 
Gibbs. The original is now in the Cavendish Laboratory. 
In 1901 the Royal Society of London awarded him the 
Copley Medal, the highest honour it is in their power to 
bestow : then at last Yale realised how great he was. It 
should in justice be said that his papers are by no means 
easy reading and would hardly be intelhgible to those who 
were not experts in the subject. I had myself personal 
experience of how little his work was known in his own 
country. When a new University was founded in 1887 
the newly elected President came over to Europe to find 
Professors. He came to Cambridge and asked me if I 
could tell him of anyone who would make a good Profes- 
sor of Molecular Physics. I said, “ You need not come to 
England for that ; the best man you coxJd get is an Ameri- 
can, Willard Gibbs **. “ Oh,*’ he said, “ you mean Wol- 

cott Gibbs,” mentioning a prominent American chemist. 
“No, I don’t,” I said, “I mean Willard Gibbs,” and I 
told him something about Gibbs’ work. He sat think- 
ing for a minute or two and then said, “ I’d like you to 


give me another name. Willard Gibbs can’t be a man 
of much personal magnetism or I should have heard of 

Some of the students who attended my lectures were 
prominent athletes, and they were good enough to show 
me something of the methods of training those who were 
to represent Yale in the Inter-University sports. The 
captain of the football team showed me how they taught 
their men to tackle. I saw hurdlers do splits on a mattress 
with one leg stretched out in front and the other behind to 
train them to get over the hurdles with their legs nearly 
horizontal. In America they take a great deal more 
trouble over the technique of their sports than we do in 

When I arrived in New Haven the spring flowers 
in the woods not far from the town were at their best. 
Bluetts, a flower something like a Tritelia, were very 
plentiful and there were great drifts of a red-and-yeUow 
aquilegia, neither of which grow in England. The spring, 
however, only lasted for a short time and before the end 
of my stay was followed by a heat wave. This was 
tolerable in New Haven, as by taking a ride outside a tram- 
car just before going to bed one could get cooled down 
and able to sleep without difficulty. It continued, how- 
ever, in full force at New York when I was on my way 
home, and a heat wave in New York is one of the most 
disagreeable things I know. The nights are hotter even 
than the days and it was impossible to get sound sleep. 
I was thankful when I got on the boat and was on my way 
back to England. 

I visited Yale again twenty years later, when I went 
for the opening of a magnificent new chemical laboratory, 
and found its growth in the interval had been phenomenal. 



The number of Professors had. more than doubled, many- 
new laboratories had been built and, perhaps the greatest 
change of all, there had been a very large increase in the 
buildings of the University by the erection of the Harkness 
Buildings. These, which cost many millions of dollars, 
were the gift of the Harkness family and are intended to 
supply residential quarters for the undergraduates. The 
buildings form a series of courts modelled after the most 
famous courts of Oxford or Cambridge Colleges, and the 
tower is a copy of the tower of St Mary’s Church, 
Shrewsbury. Architecturally I do not think the scheme 
has proved very successful. The copies of the courts are 
smaller than the originals. There is, for example, a copy 
of the Great Court of Trinity College, Cambridge, on a 
much smaller scale. Now the impressiveness of the Great 
Court is due not only to the proportion between the height 
of the building and the side of the square — a great deal 
depends on the size of the square. If this were reduced the 
dignity of the Court would suffer. But, apart from archi- 
tectural considerations, these buildings enable Yale to 
accommodate a large number of students in the University 
itself. It introduces to some extent the College system of 
Oxford and Cambridge to Yale, each of the Courts of Yale 
functioning hke a College at Oxford or Cambridge. One 
thing, however, had not changed : the new Professor of 
Physics, Professor Zeleny, like his predecessor. Professor 
Bumstead, was an old pupH of mine. 

The progress at Yale was typical of that made in most 
of the other universities in America. The State univer- 
sities who depend upon grants received from the State, 
were now receiving very much larger ones, while the 
eastern universities such as Harvard, Yale and Princeton 
had all received magnificent endowments from generous 



benefactors. The teaching staffs of the universities had 
been increased until in the larger ones there were Professors 
and teachers in almost every branch of intellectual activity. 
New laboratories had been built which were comparable 
with those of any country in the world in size and equip- 
ment, and new buildings had been added which were 
pleasing to the eye and well suited for the purpose for 
which they were intended. 

Besides the increase in the number of Professors there 
had been a greatly needed increase in their salaries. When 
I first went to America in 1896 these were quite inadequate. 
Unless a Professor or his wife had private means, it was 
impossible for them to Hve in even moderate comfort or 
for the wife to have any leisure from household duties. 
Benefactors were willing enough to leave money for build- 
ings which would bear their names, but money for salaries 
was hardly procurable. I remember on my first visit, 
when I had unexpectedly to make a speech at a dinner of a 
society of very wealthy men, I pointed out how hard it 
was in a country where rent and servants’ wages were as 
high as they are in America, to live on a salary of ^(^500 
a year, which was considered the normal salary in those 
days for a Professor. They said they did not beUeve that 
any of them did, for they all married rich wives. Cer- 
tainly an experience I had seems to show that they were 
expected to do this. There was a Chair of Physics vacant 
in an American University, and two or three English 
physicists had been suggested for it. The President of 
the university wished someone to see them, and report on 
the impression they made at an interview. The American 
Ambassador asked a few physicists, including myself, to 
meet them at the American Embassy. The Ambassador 
took no part in the discussion until it came to the ques- 


tion of the salary ; then he said, that though the salary 
was low, many wealthy men lived near to the univer- 
sity. These men had daughters, and Professors held a very 
good social position in America so that the successful can- 
idate would have no difficulty in procuring a wealthy 

I beheve that the normal salary of a Professor is now 
about $6000. Before the depression in the United States 
came along the universities had difficulty in finding men 
to fill their junior posts such as Demonstrators or Assistant 
Lecturers, as men who had done well in their university 
course had no difficulty in getting employment in industrial 
concerns with the possibility of getting a very large in- 
come if they made good. It must be remembered, how- 
ever, that the large salaries were given to those who had 
shown great powers of organisation, not to those who were 
engaged on the research work connected with the industry. 
Again, the tenure of these industrial posts was not nearly so 
secure as that of a Professorship, not only because firms 
might get into financial difficulties, but also because unless 
a man was efficient he was dismissed, and that in com- 
mercial posts the standard of efficiency to be reached to 
avoid dismissal was higher than in university ones. 

Football as played in America differs very materially 
from Rugby football in England. In the first place, the 
costume is different ; the players are much more padded 
than they ever were over here, and look rather like the 
advertisements for Michelin tyres. One of the most im- 
portant differences in the rules of the game is that in America 
the captain of the team may, during the game, replace 
one player by another held in reserve. This is allowable 
not only when the first player has been injured, but also 


if he gets tired, and even if he is merely not playing well, 
so that it not infrequently happens that at the end of the 
game hardly any of the players have been playing from the 
beginning. If substitutes are to be allowed for injured 
players, which at first sight seems very plausible, it would 
seem to be necessary to make the rule as wide as it is in 
America, otherwise you would have to define what amount 
of injury qualified for substitution, which would result 
in continual wrangling. The rule is defended in America 
as improving the quahty of the play, since if a university 
can supply two good teams, the men in the team which 
plays fust will play harder if they know they wiU be replaced 
when they get tired, than would be advisable if they had to 
last through the whole of the game. Between two uni- 
versities of the same size the system may have advantages, 
but between a large university and a small one it obviously 
gives much greater advantage to the large one. It would 
increase the difficulty of arranging matches between the 
universities, and such teams as the Services, Old Merchant 
Taylors, Edinburgh University and the like. These find 
it difficult enough to get together a team of fifteen ; it 
would be vasdy more difficult to get the much larger 
teams required under the American system. 

Another difference is that under our system you are not 
allowed to tackle anyone who has not got the ball, but in 
America it was not so. What is called interference was 
allowed. When one of a team has got the ball and is running 
with it, the forwards on his side arrange themselves in a 
wedge-like formation in front of him and try to force a 
way through the opposing team. This led to many fatal 
accidents and the wedge formation is now forbidden, but 
the forwards are still allowed to tackle men who are trying 
to get to the man with the ball. 



( The applause at a university football match is carefully 
organised. Students from the universities competing are 
grouped together under a leader, and when he thinks the 
appropriate time has come he waves his baton and his 
chorus give the “ College yell.” 

In a close match the audience is roused in this way to 
a state of great excitement. I have seen girls jump on 
their chairs and shout “ Kill him ! kill him ! ” when 
one of the team they did not favour was running with the 
ball. 7 

The rules for the scrum too are different. The ball is 
not thrown into the scrum by the half-back of the side 
who has the ball ; it is carried into the scrum by a player 
on that side, and he puts it down in the scrum, calling out 
as he does so a series of numbers, say 5-1-7 — this means 
that he is going to push the ball to the player who is called 
5 ; 5 must then push to player i, and i to 7, and so on. 
If they do not get away with the ball and the scrum 
has to be reformed, the process is repeated, and even a 
third scrum may be formed ; but if at the end of this the 
side with the ball has not gained 10 yards, the other side 
takes the ball and puts it down in the scrum. This is the 
reason why at the first time the ball is put down, a pole is 
placed level with it ; this pole is connected with another 
by a rope 10 feet long, and this is also driven into the ground 
in the direction of the enemy goal, with the rope stretched. 
If after three downs the ball is not past the second post, 
the other side takes it. 

There is much more organised strategy in American 
football than in ours : each player in a match has a number* 
What that number is nobody but the other members of his 
side knows. This enables instructions to be given to the 
team without the other side being any the wiser. Most 


elaborate precautions are taken to keep the code secret, 
and I never heard of a case when it had leaked out before 
a match. 

The training of their football teams is very systematic 
and goes on even when the football season is over. I saw 
the training in tackling at Yale when I was lecturing there. 
The teams were lined up in a large barn ; from the ceiling 
a heavy sack was hung by a rope. The trainer of the 
team pulled the sack out a considerable distance and then 
let it go. Just as the rope got nearly vertical he called out 
a number and the man with that number had to fling him- 
self on the sack and stop it before it got to the place where 
it had been before the trainer pulled it away. The result 
of this is that the tackling in the university matches is 
magnificent. The same may be said of their drop-kicking, 
which they also practise under all kinds of conditions. The 
play in American football is not so open as in ours ; in it 
scrum play is predominant. One does not often see long 
runs by the three-quarter backs when the ball passes from 
one man to the other right across the field, and then back 
again until the enemy’s line is crossed. This to my mind 
is the most thrilling thing in football, or indeed in any 
game I have ever seen. 

Watching football in America is much more expensive 
than it is in England. The cheapest seat at an Inter- 
University match is five dollars. In spite of this the 
attendance is so great that the income of the football club 
is very large. I have been told that the Princeton Club in 
1932 received a milHon dollars from this source. Foot- 
ball is, however, the only game which brings in a profit. 
Rowing, baseball, have all to be supported from the money 
earned by football. The same is true in Cambridge : the 
finances of the Rugby Club are very prosperous, and they 


are liberal in their grants to other clubs ; they even 
founded a Lectureship in Classics in the University as a 
tribute to the Rev. J. Gray, of Queens’ College, who was 
their President for many years. 




Visits to Canada and Berlin 

1 WAS elected President of the British Association for 
1909, when the meeting was to be at Winnipeg. It was 
just a quarter of a century since the Association had, for 
the first time in its history, held its meeting outside the 
British Isles. Then it met at Montreal with Lord Rayleigh, 
who at that time was Cavendish Professor in Cambridge, 
as President, while Lord Kelvin was President of Section 
A. The Association met again in 1897 at Toronto when 
Sir John Evans was President. It was striking evidence of 
the immense strides which Canada had made in a quarter 
of a century that, at the meeting in 1884, Lord Rayleigh 
paid a visit to Winnipeg, and found that it had not 
developed beyond the stage when they were ploughing up 
the streets to get rid of the ruts and make the surface more 
even. On our arrival we found it a large and prosperous 
city, with fine buildings set on broad and well-kept streets, 
and with a population of 200,000. 

My wife, brother and son accompanied me on my visit, 
and in August 1909 we travelled from Liverpool to Quebec 
by the C.P.R. boat the Empress of Ireland. We sailed up 
the St. Lawrence to Quebec, and arrived there one evening 
in the late twilight. The approach to Quebec was so 
beautiful that after all these years I often try to recall it. 
The river was quite calm, there was no wind, there was 
not a cloud in the sky, which made a deep violet back- 
ground for a crescent moon over the Heights of Abraham. 


We stayed the night at Quebec and the next morning 
walked about the town, which was very different from 
any we were to see afterwards. The population is mainly 
French-Canadian. French is the prevalent language : the 
buildings are old, picturesque and the streets tortuous. 
There is a Roman CathoHc university. The inhabitants 
are mostly Roman Cathohcs, though many of them have 
Scotch names. They were at the time of our visit ardent 
admirers of Sir Wilfred Laurier, the Prime Minister, who 
was one of themselves, and they had very exalted ideas of 
his powers, A story current when we were there was that 
one of them had asked who would succeed Eling Edward, 
and when he was told it would be the Prince of Wales, 
said, Why, has he such a pull on Laurier as all that ? ” 

In the afternoon we went to Montreal, and after staying 
a few hours there, started on our way to Wiimipeg. 
Thanks to the kindness and hospitality of the Canadian 
Pacific Railway Company the journey was very eiyoyable 
and interesting, and we arrived at Winnipeg without 
incident. The railway station at Winnipeg is one of the 
most cosmopoHtan places in the world. It is the one 
on which the streams of immigrants from all countries 
in eastern Europe converge: Russians, Lithuanians and also 
Doukhobors, whom I had never heard of before ; they 
are a most industrious and well-behaved race, but it is part 
of their religion to walk in procession on one day in the 
year without any clothes. This makes a difficult problem 
for the local pohce to deal with. Very few of these 
immigrants know any Engfish when they arrive and some 
of them do not seem to learn quickly. During our stay 
in Winnipeg the Mayor gave a dinner to some of the 
officials of the Association, and Sir William White and I set 
out to walk to his house, which we were told was quite 


near our Kotel. We got lost and had to ask our way, and 
we had to ask six people before we found one who 
understood English. 

The educational authorities seem to deal with this 
question very effectively : all the teaching is in Enghsh. 
They have a very large room, and when a child with no 
English first comes to the school it is not put in any class, 
but just sent into this room to play with the other children. 
After about three months of this, most of them pick 
up enough Enghsh to be able to follow the lessons well 
enough to profit by them. We were told that sometimes 
forty-two languages and dialects might be heard in the big 

Professor Rutherford was President of Section A 
(Physics) ; Professor H. E. Armstrong, of Section B 
(Chemistry) ; Dr. Smith Woodward, of Section C 
(Geology) ; Dr. Shipley, of Section D (Zoology) ; Sir 
Duncan Johnstone, of Section E (Geography) ; Sir 
WiUiam White, of Section F (Engineering) ; Professor 
J. L. Myres, of Section G (Anthropology) ; Professor 
Starling, of Section H (Physiology) ; Lieutenant-Colonel 
Sir David Prain, of Section K (Botany) ; and the Rev. H. B. 
Gray (Education). Among others attending the meeting 
were Professor Larmor ; Professor Poynting, who gave 
us a paper on “ The Pressure of Light ; Professor Lamb, 
Professor MacMahon, Professor MacDonald from Aber- 
deen, Professor Hobson, Professor Lyman and Professor 
Bumstead from Yale. Among the foreign visitors I may 
specially mention Dr. E. Goldstein from Berhn, one of the 
earhest workers on the discharge of electricity through 
gases, and who, in the course of researches extending over 
more than fifty years, discovered many very important 
phenomena. He was a pupd of von Helrnholtz and worked 


at first in the Physical Laboratory at Berlin and later in 
the Observatory at Potsdam ; his first paper was pubhshed 
in 1874 and was followed in quick succession by others, 
each containing some interesting discovery : for these he 
was awarded the Hughes Medal by the Royal Society in 
1908. He died in 1930 at the age of eighty. He read a 
paper to the Association on the phosphorescent spectra 
given out by some organic compounds when cooled to 
the temperature of liquid air. Another foreign visitor 
was Professor H. Miinsterberg, Professor of Experi- 
mental Psychology at Harvard. He was exceedingly 
popular with his students ; indeed they were accused 
of altering the first line of a well-known hymn to “ Ein 
Miinsterberg ist Unser Gott'\ I think the meeting was 
successful. The various Presidential Addresses were weU 
attended and the discussions well maintained. As was 
natural in a meeting at the very centre of wheat production 
in Canada, a Hvely interest was taken in the prediction 
made by Sir William Crookes in his Presidential Address 
to the British Association at Bristol in 1898, that there 
would, in the not very distant future, not be enough wheat 
to support the increased population. Actually, since this 
prediction things have gone the other way, and the produc- 
tion is more than the population can consume, or rather, 
can afford to buy. It was very interesting to hear how the 
breeding of a new kind of wheat, which would ripen a 
fortnight earher than the kinds known at present, would 
increase by miUions of acres the area on which wheat could 
be grown. 

The evening Discourses were given by Professor 
Tutton on “ The Seven Styles of Crystal Architecture ” ; 
by Professor Herdman on “ Our Food from the Water ” ; 
by Professor H. B. Dixon on “ The Chemistry of Flame ’’ ; 



and by Professor J. H. Poynting on “ The Pressure of 
Light”. These, as well as the Presidential Addresses, were 
given in the Walker Theatre, one of the largest playhouses 
in the Dominion at that time. The Members of the Associ- 
ation received very generous hospitahty, and had the 
opportunity of learning much about the conditions of Hfe 
in the newly developed regions in Canada. One thing 
that struck me very forcibly was the importance of the 
work done by the Young Men’s Christian Association in 
this, and indeed in aU the other towns I visited in Canada. 
The Association has a very fine club-house, much larger 
than is usual in this country, and a Committee which is 
active in getting into touch with young men when they 
arrive, inviting them to join the Club, giving them 
opportunities of making friends and of joining in many 
social functions. This must mean a great deal to a young 
man, not only when he first comes to the town but as long 
as he stays there. Another feature which struck me is the 
great part which the big hotel plays in the social life of the 
place. Everyone who wishes to meet a friend in the even- 
ing seems to think that the best chance of finding him is 
to go to the lounge of the hotel. Many pohticians either 
entertaining their constituents, or arguing with each other, 
are to be found there, and business men meet to fix up their 
deals. If anyone wishes to entertain, he does so at the 
hotel and not at his own house. This custom seems to 
have spread to this country. When I was in Dublin re- 
cently the lounge in my hotel reminded me very strongly 
of those I had seen in Canada nearly thirty years ago. 

We got an example of the mineral wealth of Canada 
when we were at Winnipeg, for it was discovered during 
our visit that the sand used for spreading over the roads 
contained platinum. Long before this the railroads in the 


cobalt region in Ontario had unwittingly been metalled 
with silver ore. 

The hospitahty of the Canadian people did not cease 
with the meeting of the Association, for as soon as that was 
over a large party of us were taken on a most entrancing 
trip to the Pacific, and then back again to Winnipeg by a 
different way. The long train by which we travelled was 
equipped with an observation car, with cooks, waiters, etc., 
in fact it was an hotel on wheels. Our practice was to 
travel from one place to another by night, spend the day 
in seeing the place at which we had arrived, or perhaps 
make an excursion and stay two days. Wherever we 
stopped we were entertained by the residents, and I had 
to make a speech thanking them for their hospitality. 
This was usually very pleasant and I quite enjoyed it, but 
at one place they had erected a triumphal arch of bags of 
wheat. It had been put up hastily, and I noticed, during the 
Mayor’s speech of welcome, that the arch was shaking in 
a way which seemed to me to indicate a speedy collapse. 
As we were standing under the arch I thought it best to 
make the warmth of my thanks very pronounced, so as to 
compensate for their brevity. I shall not make any attempt 
to describe in detail the scenery through which we passed. 
Those who have made the trip will find it hard to beheve 
that it is surpassed by any in the world. At first we 
travelled for many hundred miles through the prakies, 
covered with wheat almost ready for the harvest. Each 
puff of wind made a wave travel over them to the horizon : 
we might to all appearance have been sailing over a great 
ocean, instead of running on a railroad through a vast 
cornfield. The effects at stinset or sunrise were most 
beautiful and remarkable. After passing over the prairies 
we reached Banff, and saw the buffaloes which flourish in 


the immense park reserved for them. Then came the 
Rockies and snow mountains, with visits to Glacier and 
Lake Louise. When we were looking down the lake 
from near the hotel, the other end, which had been quite 
distinct, suddenly became obscure, although no fogs or 
clouds had been visible. A few seconds after we heard a 
great noise and the end of the lake soon got clear ; an 
avalanche had fallen while we had been looking. Some 
little way before we reached Vancouver, which was our 
next stop, we ran by the side of the Fraser River : it was 
so full of salmon that it was quite red. It seemed almost 
as if they were so thick that an agile very hght-weight 
might have crossed the river using them as stepping-stones. 
As we approached the Pacific the chmate changed and 
became much more like that in England. The heat was 
not so fierce nor the air so dry as it had been before. Van- 
couver we found a very busy and apparently flourishing 
place. It had a university, parks, golf-links and garden 
suburbs. There was a land boom on when we were there, 
and everyone seemed to think he was going to make a 
fortune by buying, or getting an option on, some piece of 
land, and then selling it at a higher price. All classes 
seemed to be infected by the rage, and prices were forced 
up until some pieces of land sold for more than they would 
have fetched if they had been in the heart of London. 

A few hours’ sail from Vancouver is Victoria. This 
is not a commercial place but one of fine houses, beautiful 
gardens and well-kept lawns. It seems quite a haven of 
rest after the busde and noise of Vancouver. 

We returned to Winnipeg by a different route, travel- 
ling ftom Edmonton by the Canadian Northern Line and 
going through Calgary to Winnipeg. From Winnipeg 
we went to Toronto to stay with my old pupil and friend 


Professor McLennan, who was Professor of Physics in the 
University, and had succeeded in inducing the Govern- 
ment of Ontario to find the funds for an exceedingly fine 
laboratory, large, very weU designed, and well provided 
with instruments both for research and lectures. The 
laboratory was very elaborately organised. For example, 
in all but the advanced classes there was a file for each 
lecture in the course, giving the subjects to be dealt with 
in the lecture and the order in which they should be taken, 
mentioning, too, the experiments which should be made 
and the apparatus which should be used. This method 
has the advantage that if a Lecturer is unable to lecture, a 
substitute can give the lecture at very short notice. I 
should be afraid that this method would tend to make the 
lectures rather dull. Most people, I think, find that their 
lectures are more easily followed by their pupils if there is 
some spontaneity about them, if the Lecturer has to find 
the words as he goes along, and not read them from a 
manuscript. It was very dehghtful to find “Mac” going 
so strong, and taking such a prominent part in the general 
business of Toronto University. From Toronto we went 
to Niagara. We had been hving in trains for about thir- 
teen days and had spent most nights travelling. I thought 
I had slept well in the train, but I more than slept the clock 
round the first night in the hotel at Niagara. I suppose 
sleep has two dimensions, depth as weU as length, and that 
the sleep one gets in trains does not rest one as much as the 
same length of sleep in bed. We returned from Niagara 
Falls to Quebec through Montreal, and visited the Uni- 
versity there. W e came home from Quebec by the C.P.R. 
boat the Empress of Britain. What struck me very forcibly 
on my visit to the farming district in Canada was the hard 
struggle the farmers had for the first few years they were 



on the land. Their standard of living, until they had made 
good, was not higher than that of an English agricultural 
labourer. Another point was the loneliness of their lives 
in the winter. This has been relieved now by the dis- 
covery of wireless, of the telephone and the production of 
very cheap motor cars ; but at the time of our visit it was 
very acute. A medical officer told my wife that many of 
his women patients dehberately unpicked their dresses 
in the winter so that they might find something to do in 
sewing them up again; without this they were hable to 
go off their heads. 

Visit to Berlin, October igio 

In October 1910 my wife and I went to Berlin to 
attend the celebration of the centenary of the foundation 
of Berhn University, where I was to represent Cambridge 
University. Just as we were about to start, my wife 
discovered that the hood of my doctor’s gown was much 
too old and shabby to be worn on such an august occasion, 
so a new one had to be procured. There was no time 
to undo the parcel, so it was thrust into my portmanteau 
just as it came. This led to trouble with the custom-house 
at the frontier, for the hood when folded up is a peculiar- 
looking object, and the official when he opened the parcel 
wanted to know what it was. This took some time to 
explain ; then he wanted to know what it cost. Cam- 
bridge tailors do not send in the bill with the goods, so 
that I did not know, and this again took time to settle, and 
the result was that we very nearly missed the train. How- 
ever, we arrived in Berlin safely, where we stayed with 
Professor and Adrs Warburg. Professor Warburg was the 


Director of the “ Reichsanstalt ”, an institution for research 
in physics which had been founded by Werner Siemens at 
the suggestion of Helmholtz. It was the first of the labora- 
tories of the type of the National Physical Laboratory 
at Teddington in England, or the Bureau of Standards at 
Washington, intended for researches which cannot con- 
veniently be made in laboratories in universities, such as 
those which have to be extended over long periods, or 
which require very elaborate or expensive apparatus, or 
whose interest is mainly in their technical apphcation, 
or for the comparison of different standards of physical 
quantities such as the ohm. Von Helmholtz was the 
fet Director of the Reichsanstalt at Berlin and Professor 
Warburg was his successor. 

The Commemoration began on the afternoon of 
Monday, October lo, with a religious service in the 
Dom Kirche. The music was magnificent but the build- 
ing itself very disappointing. 

The reception of the delegates on Tuesday was a very 
striking scene. The delegates in their academic robes of 
all colours were in the centre of the room, framed by the 
members of the various student corps in their uniforms, 
standing against the walls. There were several speeches 
and the proceedings closed with the singing of Gaudeamus 
igitur. El the afternoon at 3 o’clock there was a banquet 
to about 600 guests. Bethmann HoUweg (the Chancellor) 
was in the chair, with a prince on either side. After he 
had made a short speech, the loving-cup was passed round. 
He just took a sip and handed it to one of the princes, who 
treated it in quite another fashion. He threw his head 
back and drank and drank until it seemed as if he would 
never stop. At last he did, and then, holding the cup over 
the table, turned it upside down, and not a drop fell out. 



The effect of this feat on the learned assembly was inde- 
scribable : they cheered, they shouted, they waved their 
napkins ; some of them even stood on their chairs to do so 
more effectively. It was for all the world j ust like a ‘ ‘bump 
supper ” after the boat-races in Cambridge. 

There were several speeches, but these could not be 
called “ after-dinner speeches ”, for there was one between 
each course. They were much more serious affairs than 
those in England. The speaker left his place and walked 
to a pulpit : when he had got into this, he took out a 
manuscript from his pocket and read steadily for about 
a quarter of an hour. Then he went back to his place at 
table and the next course was served. The only German 
I can remember who made a speech and did not read 
a lecture was the great classical scholar. Professor 
Wilamowitz-MoUendorff. Professor Mahaffy of Dublin, 
who replied for the British delegates, made a humorous 
speech in German and seemed to enjoy making it. One 
of my neighbours at dinner said with great surprise, 
“ Why, he is laughing at his own jokes 

The result of these speeches was that, though we had 
commenced dinner at 3 o’clock, we had not finished it 
when we had to leave to attend a performance of Figaro 
at the Opera at 8, and this, which went on untU ii, closed 
a very strenuous day. 

On the next day there was a lecture in the morning 
and a garden party in the afternoon. We also saw a great 
number of Zeppelins, which were parked in a large field. 
Few of us, I think, had any idea that Germany had so 

In the evening the students had a “ Commers ”, which 
seems to have been somewhat uproarious. The supply of 
beer which was provided was on the scale of, I think, two 


gallons per student, but before lo o’clock this had all 
been drunk, and there were hundreds of thirsty students 
clamouring for beer and not able to get it. There was 
a disturbance and some damage was done. When the 
Kaiser heard of this, he sent for some of the ringleaders 
next morning and rated them as a College tutor might 
rate an undergraduate who had got into a scrape, only he 
did it more effectively. He is reported to have said to 
them : “ Why do you drink so much beer ? Why don’t 
you play games like English students do ? If you did you 
would not be the disgusting-looking objects you are.” 

We left Berlin on the next day. There was a railway 
strike on in France, and though we started in the hope 
that we might be able to reach Calais, we could not do so 
and had to go to Os tend, and the crossing was very rough. 

The working classes in Berlin evidently disliked the 
English at this time. One morning when my wife was 
out driving with our host’s daughter, she happened to look 
back and saw some men shaking their fists at the carriage. 
On asking what was the reason, she was told, “ Oh, 
they have recognised that you are an Enghshwoman ”. 
in mihtary circles the Kaiser himself came in for much 
criticism for not being sufficiently anti-English. The 
Crown Prince was their hero, who did not fail in this 
respect. I have never been able to beheve that the Kaiser 
was responsible for the war. Unless the mihtary party had 
changed greatly in the interval between 1910 and 1914, 
they wanted war and wanted it badly. Unfortunately 
they managed to get their way in the end, but I do not 
beheve that the Kaiser was the instigator. 



War Work : Cambridge during the War 

T he work I did in connection with the war was 
mainly in association with the Board of Invention 
and Research (B.LR.). This Board was instituted 
in July 1915 when Mr Arthur Balfour was First Lord, 
for the purpose of giving- the Admiralty expert assist- 
ance in organising and encouraging scientific effort in 
connection with the requirements of the Naval Service. 
The functions of the Board were : 

[a) To concentrate expert scientific enquiry on certain 
definite problems whose solution is of importance 
to the Naval Service. 

(6) To encourage research in directions in which it is 
probable that results of value to the Navy may be 
obtained by organised scientific effort. 

(r) To consider schemes of suggestions put forward by 
inventors and other members of the general pubhc. 

There was a Central Committee of which Lord Fisher 
was President. The other members were Sir George 
Beilby, Sir Charles Parsons and myself. Vice-Admiral 
Sir Richard Peirse was appointed Naval Member of this 
Committee in July 1916. The Board had its offices in 
a house in Cockspur Street which Lord Fisher character- 
istically rechristened Victory House. 

The Central Committee was the Governing Body, 
and its approval was required before any proposal could 


be adopted. It was assisted and advised by a panel of 
scientific experts. The original panel was Professor H. B. 
Baker, Sir William Bragg, Professor Carpenter, Sir 
WiUiam Crookes, Mr Duddell, Professor Frankland, 
Professor Bertram Hopkinson, Sir Oliver Lodge, Sir 
William Pope, Lord Rutherford (then Sir Ernest Ruther- 
ford), and Gerald Stoney. Sir Richard Threlfall was 
added to the panel at a later date. The first Secretary 
was Captain Crease, R.N., who was succeeded by Sir 
Richard Paget. 

The most urgent need of the Admiralty at the time 
the B-LR. was instituted was some method of detecting 
submarines, and means were taken at once to start experi- 
ments with this subject. The most obvious method of 
detecting a submarine is by the sound it makes. It had 
long been known that sound travels weU through water, 
and various methods had been devised for detecting 
it. Thus, if a tube is closed at one end with a 
diaphragm and lowered into water through which 
sounds are passing, the diaphragm will be thrown into 
vibration and produce in the air in the tube sound 
waves of the same pitch as those in the water. 
These can easily be detected by the ear or by a micro- 
phone. The problem of detecting a moving submarine by 
the sound it makes is a most difficult and comphcated one. 
In the first place, the vessel which is hunting the sub- 
marine itself produces noises when it is not at rest, by 
its engines, its motion through the water, and so on. In 
bad weather these drown all others. Thus a microphone 
submerged in the water and carried along by a ship will 
give tongue even when there are no submarines in the 
neighbomhood. One thing in our favour was the remark- 
able power the human ear can acquire m picking out a 


particular kind of sound even when it is mixed up with 
others very much louder. An example of this is that 
workmen in an engineering workshop where there is a 
din that nearly deafens those who are not used to it, can 
talk to each other without raising their voices. We found 
that observers after long practice acquired the power of 
picking out the sound of a submarine even when mixed 
up with other sounds, and that better results were ob- 
tained by careful and prolonged traming of the observers 
than by increasing the sensitiveness of the instruments. 
The sound given out by a submarine is not a pure note, 
but a noise made -up of a great number of notes of different 
pitches. In such a case as this resonance does not help 
much, and since the character of the note depends upon 
the proportions between the intensities of the different 
notes, any resonance effect will destroy the quality of the 
noise of the submarine and make it more difficult to detect. 
It would be much easier than it is to detect a submarine, if 
it were a musical instrument and gave out a definite note. 

Even if we can identify a noise as due to a submarine 
we require, if we are to catch it, to know the direction 
from which it comes. The velocity of sound through 
water is about 4-3 times that through air. This will be 
the proportion between the wave-length in water and ak 
respectively. An opaque object placed in the way of 
a wave will not cast a definite shadow unless the diameter 
of the object is many times the wave-length. Thus if we 
determine the dkection of the sound in water by placing 
an object in its way and finding where the shadow is, we 
have to use much larger objects than would be necessary 
in ak. 

The B.I.R. began then attack on the detection of sub- 
marines by obtakikig from Sk Ernest Rutherford a report 


on the various methods which had been employed, or 
suggested, for detecting sounds in water. He reported that 
the microphone method was by far the most promising. 
The Board determined to make arrangements on a sub- 
stantial scale to develop this method, especially on the side 
of increasing its power of fixing the direction from which 
the sounds came. They were fortunate in being able to 
secure the services of Professor, now Sir William Bragg, 
as the director of this research. It was arranged with the 
Admiralty that the research should be made at the Naval 
Experimental Station at Hawkcraig, where Captain Bryan 
had been making experiments for the Admiralty on sound 
detection since June 1915. Huts to serve as laboratories 
were erected by the B.I.R. for Bragg’s work, and it paid 
the salaries of two trained physicists to assist him in his 
experiments ; a new workshop and a skilled workman 
were also provided. The plan was that Captain Bryan 
should continue his work under the direction and at the 
expense of the Admiralty, while Professor Bragg’s work 
would be under the control and at the expense of the B.I.R. 
It was intended that these two branches should co-operate 
and inform each other of the progress they had made. 
Professor Bragg took charge in May 1916 and made good 
progress in the development of detectors. Great diffi- 
culties were, however, found in getting opportunities for 
testing these at sea. The Submarine Committee of the 
B.LR., after a visit to Hawkcraig in September 1916, 
reported that conditions were unsatisfactory. One cause 
of this was that the Navy was then divided into two 
parties, Fisherites and Anti-Fisherites, and that every 
scheme associated in any way with Lord Fisher was 
regarded by the latter party with grave suspicion and 
dislike. There was so much prejudice of this kind that I 

209 p 


believe B.LR. was said by the Anti-Fisher party to stand 
for Board of Intrigue and Revenge. Towards the end of 
1916 it was decided to transfer the work of the B.LR. on 
submarines from Hawkcraig to Harwich, and a laboratory 
was built at Parkeston Quay. This change improved 
matters, but it had involved a loss of several months just 
at the time when a detector had been devised which, as 
far as could be tested by experiments on a small scale, 
promised to be of service in detecting submarines. It was 
essential that it should be tested by fitting the apparatus 
to some vessels in the Fleet and seeing how it behaved under 
service conditions. It was only to be expected that under 
these conditions defects would be detected which would 
require further experiments at the Experimental Station to 
overcome. If it had not been for the delays just mentioned, 
efficient submarine detectors would have been available 
months earlier than they were and much loss of life 

It would be much easier to detect submarines if the 
sound they produce had a definite pitch, for then we could, 
as in the detection of “ wireless ’’ waves, make use of the 
principle of resonance. Practically, we could make them 
produce such a note at our wiU if we directed water waves 
of a definite pitch on to them and listened to the echo. 
These waves would have to travel from the ship on the 
look-out for submarines and back again, and unless some 
contrivance equivalent to that used for searchUghts were 
adopted, the spreading out of the waves would reduce 
their intensity so much that it would in practice be im- 
possible to detect the echo except at very short distances. 
Fortunately we can produce the “ searchhght ” effect much 
more easily with short waves than with long ones. If, for 
example, a flat square plate immersed in water is made to 



vibrate at right angles to its flat surface so quickly that the 
wave-length of the waves it produces in the water is small 
compared with the length of a side of the square, the waves 
wiU be concentrated along the direction at right angles to 
the square. The angle of the cone in which they are con- 
fined will be proportional to the ratio of wave-length to the 
side of the square, so that the smaller the wave-length the 
greater the concentration. Professor Langevin, whom I 
am proud to be able to say is an old pupil of mine, dis- 
covered, when working in France at the detection of sub- 
marines, a method by which oscillations could be produced 
in plates of quartz, so rapid that their wave-lengths were 
small compared with the size of the plate, and which 
allowed a great amount of energy to be put into the vibra- 
tions, so that the sound they produced was very intense. 
This method depends on a recondite property of quartz, 
which had been discovered years before by an investi- 
gation made solely with the object of increasing our 
knowledge of physics without any thought of practical 
application. There were many other instances in the war 
of the practical apphcations of physical phenomena known 
previously only to students of the higher parts of physics. 
Indeed we should expect that any part of our know- 
ledge of the properties of matter or of the laws of physics 
might receive a practical appHcation. One very important 
American company, noted for its successful applications 
of physics to practical purposes, is said to instruct the staff 
of its research department not to trouble about industrial 
applications, but just discover something and leave it to 
the staff of another department to find out how to make 
it pay, and they generally do. 

Besides devising physical apparatus to detect submarines 



some experiments were made on more unconventional 
lines. It was suggested to B.LR. that if sea lions were able 
to hear sounds made under water they might be used to 
detect submarines, and thus these might be hunted down 
by a pack of submarine hounds. Some performing sea 
Hons were hired and experiments were made with tiem, 
at first in swiniming-baths, afterwards in Bala Lake in 
North Wales, and finally in the Solent. The method used 
was to make a sound under water with a “ buzzer ”, or 
by hitting a metal plate with a hammer, and to place food 
at the source of the sotmd. Thus by following up the 
sound the animal would always find food, and it was hoped 
would get to look on it as the call of a dinner-beU. The 
sea lions were found to hear quite well under water and 
were able to detect the sound at as great a distance as the 
detecting instrument we were using at the time. After a 
short training they learned to associate sound with food 
and would swim up to its source. In Bala Lake, where the 
most successful experiments were made, they would some- 
times come to the food from three miles away. They 
were, however, very temperamental ; sometimes they 
would only come from a fraction of this distance. On hot 
days they were decidedly less efficient than on cold ; their 
speed too was slower than might have been expected. 
They took at least forty minutes to travel three miles, so 
that any but a very slowly moving submarine would get 
away from them. If the porpoises which often circle 
round Atlantic liners come to the ship through hearing 
the noise it makes, and associating it with food thrown out 
firom the vessel, they would make much better detectors 
than sea hons since dieir speed is so much greater. In the 
Solent the sea hons were a failure : there were generally 
several ships about, and they kept turning aside to go to the 



one making the greatest noise at the place where they 
happened to be swimming. Another suggestion which 
proved worthless was to put food on buoys shaped hke the 
periscope of a submarine, in the hope that, if a periscope 
did appear above the surface of the water, flocks of gulls 
would fly to it in the hope of getting food. 

The B.I.R. and the similar institutions in France and 
America kept in touch with each other by Haison officers : 
at one time the French one in England was the Due 
de Broglie, a very eminent French physicist, and the 
American officer was my old pupil the late Professor Bum- 
stead, then Professor of Physics in Yale University, while 
Sir Ernest Rutherford, Sir Richard Paget and Captain 
Bridge visited America and France for the same purpose. 

Besides the Committee on Submarines there were 
Committees on Aeronautics, Naval Construction, Marine 
Engineering, Intemal Combustion Engines, Oil Fuel, Anti- 
aircraft, Noxious Gases and Ordnance and Ammunition. 

Part of the work of the B.I.R. was the examination of 
the suggestions and schemes sent in by inventors, and the 
general public, for dealing with problems connected with 
the war. These were so numerous that they required a 
large staff of clerks and a number of experts from the 
Patent Office to cope with them. In the first six months 
after the formation of the B.I.R. we had over five thousand 
inventions sent in, and the number increased rapidly as the 
war went on. I should think before it ended the number 
had increased to well over 100,000 ; of these not more than 
thirty proved to be of any value. Though very little that 
was important for the prosecution of the war came out 
of this cloud of inventions, its political effect was very 
considerable. Every invention sent in was examined by 
experts : no one could say that he had sent in an import- 


ant invention of which no notice was taken. If there 
had not been the B.I.R., many would have written to the 
newspapers, and created an impression that the Govern- 
ment were too casual about the war. Each air raid in 
London was followed by a crop of hundreds of suggestions 
for capturing the bombarding Zeppelins. Some of these 
were very naive. One was to have large balloons moored 
over London each carrying thick ropes heavily smeared 
with bird lime and flying at a great height. The idea was 
that the bombers, when they passed over London, would 
strike against a rope, stick to it and be captured. Another 
proposal for ending the war was more elaborate. It was 
to collect a flock of cormorants, feed them on white food, 
and peg this in horizontal and vertical lines against the 
walls of the room in which they were kept. This would 
give the walls the appearance of brick-work, the food 
representing the mortar. When they had had sufficient 
training, they were to be hberated as near as possible to 
Krupp’s works at Essen. The cormorants, when they 
saw the chimneys, would think the mortar was food, peck 
it away, the chimneys would fall down, and the Germans, 
not being able to receive arms and munitions from Krupp’s, 
would surrender. 

Proposals hke these gave no trouble : they were a 
comic rehef in a very serious and harassing drama. There 
were, however, others equally ridiculous which gave a great 
deal of trouble. For example, we received an apphcation 
firom an inventor saying that he had devised a method of 
preventing aeroplanes passing over our lines : for this 
he asked ^7,000,000. He would not say what the nature 
of the invention was, but said he would do so after we had 
given an undertaking that we would construct a piece of 
apparatus after his plans and, if it did what he claimed, give 


him the ^7,000,000. If we had accepted this offer, it would 
have obliged us to take skilled mechanics, which were very 
difficvJt to get, from important work, and go to the expense 
of constructing a thing which it was highly improbable 
would be of any use : we therefore turned it down. 
Then paragraphs began to appear in the newspapers saying 
that we had rejected a scheme which might end the war, 
even though the inventor had agreed to let the payment 
depend on the scheme being successful. This was followed 
by questions in the House of Commons, and then by 
“ leaders ’’ in influential newspapers, and a very pretty 
agitation was worked up. So much so that we received 
a request which could not be refused, that we should 
reconsider the question. We therefore decided to have an 
interview with the inventor. He asked if he might bring 
his advisers with him : to this we consented. Lord Fisher 
was not able to be present and asked me to receive the 
deputation. This proved to be a large one. There was 
the inventor himself, a mechanic, who I think honestly be- 
heved in his invention. He brought with him his financial 
adviser, a solicitor, an auctioneer — suppose because he 
expected an auctioneer to be a voluble speaker — and 
some other oddments whose vocations I do not remember. 
I told them that it had been decided to reopen the question, 
but they must understand that we should not think of 
taking any steps about it unless we had some information 
with regard to its nature. If the inventor thought the 
B.I.R. was too large a body to entrust with the secret, then 
we must try to find someone acceptable to both parties 
whose verdict we would accept. Then began a very- 
amusing scene. The inventor was full of eagerness to talk 
about his scheme, while his financial adviser was con- 
tinually stopping him, saying he must not give away the 


secret. I asked if the invention would work however high 
the aeroplanes might fly. He said it did not matter how 
high they went provided they did not go so high that 
gravity ceased to act. This was not very hopeful ; and so 
it went on; if I asked a question as to whether it would 
act under certain conditions, the inventor always started 
off by saying it would, and was stopped by his financial 
adviser or the sohcitor. The other members of the depu- 
tation said little or nothing. In the end we agreed to try 
to find an acceptable umpire. This took some weeks, 
but finally one was found. This was the invention : to 
surround our lines by a ring of iron poles, each a quarter 
of a mile high and separated from each other by the same 
distance : the poles were vertical and each pole was pro- 
vided with an engine to make it turn about its axis. 
Fastened to the top of each pole was a steel chain one eighth 
of a mile long, and at the free end of the chain there was a 
bag containing a large quantity of dynamite. When the 
poles were set spinning by the motors the chains would 
fly out and become nearly horizontal, so that the troops 
would be protected by a belt of dynamite. This prepos- 
terous scheme had been supported by many influential and 
honourable men, who however knew nothing technically 
about the nature of the invention which they thought 
ought to be investigated. The agitation had attracted 
a good deal of attention and had been an excellent adver- 
tisement for the scheme, and if it had been announced 
that the Government were considering it, it would 
probably have been possible to get a considerable response 
to an issue of bonds which were to be repaid at a high 
premium out of the 000,000 which the Government 
would pay for the invention. 

Another proposal which got considerable support 


from some influential people came from an inventor who 
claimed to have produced gold from quicksilver. It is 
true that quicksilver in a vessel containing gas at a low 
pressure sometimes gets coated over with a yellow film 
of some compound of quicksilver when a current of 
electricity passes through the gas. To some people every- 
thing that ghtters is gold, and the inventor, who had 
observed this, thought he was making gold out of quick- 
silver. This had been brought to the notice of the 
Government and again an agitation began, urging them 
to do something. Mr Arthur Balfour came to me and 
asked me to go into the matter, as questions were sure to 
be asked in the House, and the Government would be in 
a stronger position to answer them if they could say that 
they had already taken steps to have the discovery in- 
vestigated. Accordingly I suggested several experiments, 
and said if these were made in my presence I would be 
prepared to express a definite opinion on the discovery. 
These, however, were never made, for it was discovered 
that attempts were being made to induce people to take 
shares in a syndicate to exploit the discovery by saying 
that the King was taking a keen interest in it, while as a 
matter of fact His M^esty had never even heard of it. 
The Government thought that this would be quite a 
sufiicient answer to any question that might be raised in 
the House. 

Owing to my connection with the B.I.R., I saw a good 
deal of Lord Fisher between 1915 and 1918. I never 
came across anyone with such pronounced personahty, 
nor with such extraordinary driving power. His method 
was that of the mailed fist rather than the gloved hand, 
and in carrying out his schemes he made many enemies 
and hurt many people’s feelings. When different schemes 


canie before him he spent very httle time in determining 
which should be chosen, and in his choice he seemed to 
be guided by instinct rather than by reason. When he 
had made his choice, his whole energies were thrown into 
carrying it into effect. This was a great contrast to the 
practice I had been accustomed to in University matters. 
In these, much time and energy is spent in discussing what 
scheme should be adopted, so much so that one is apt 
to be tired of the scheme before it is started, and to be 
languid in carrying it out. There can be no question 
which is the better method in war-time. Lord Fisher had 
foresight and imagination as well as energy. He could see 
thepotentiaHty of inventions which in their early stages had 
been nothing but failures. He envisaged what service they 
might render if the purely mechanical difficulties were 
overcome, as there was a good chance they might be by 
skill and perseverance, and he did all in his power to 
expedite this process. Thus, in spite of great difficulties 
he had been trying type after type of submarines, and it 
was, I beheve, due to him that we had, at the begin- 
ning of the war, submarines in our Fleet. The most 
dramatic naval event in the war was the destruction of 
German warships at the battle of the Falkland Islands 
by the fast cruisers Invincible and Inflexible which he 
had introduced into the Navy. He was strongly m 
favour of using oil fuel in our ships, and he often talked 
of the desirability and possibility of submersible cruisers. 
Though he did so much to introduce into the Navy every 
possible mechanical contrivance which could make it more 
efficient, yet in his view the tactics of this mechanised 
fleet should be as full of the spirit of adventure as those 
of the old Navy. He had no use for the motto “ Safety 
First ’’ : the “ Nelson touch ” was what he always longed 


for. I remember very vividly the morning after the 
battle of Jutland; when I got to the office he was pacing 
up and down the room more dejected than any man I 
have ever seen. He kept saying time after time, “ They’ve 
failed me, they’ve failed me ! I have spent thirty years 
of my life in preparing for this day and they’ve failed me, 
they’ve failed me ! ” This was the only time I ever knew 
him to be doubtful about the issue of the war. He used to 
say : “The Government, the Army and the Navy may make 
as many mistakes as they please, but we are bound to come 
out top in the end because we are one of the lost tribes 
He had an excellent knowledge of the text of the Bible ; 
he used to say that the two things he enjoyed most were 
listening to sermons and dancing. In the noiddle of the 
war, when things were going badly, Mr Winston Churchill 
spoke in the House of Commons in favour of bringing 
him back to the Navy, a very notable thing to do, as 
Fisher’s retirement from the Navy was due to differences 
between his views and those of Mr Churchill with regard to 
naval poHcy. The next morning as soon as I got to the 
office he began, “ Have you seen what Winston said about 
me last night ? ” I said I had, and was much surprised. 

Surprised ! ” he said, “ I should think you were. There’s 
never been anything hke it since Herod made friends with 
Pontius Pilate.” 

Even trivial things he did in the grand manner. The 
notes he wrote to me from the ojSEice were on large-quarto 
paper put without folding into envelopes of the same size. 
They consisted of perhaps half a dozen lines, and often 
ended, “Yours till Hell freezes, Fisher”. He wrote, at 
the time I was working with him, his reminiscences, and 
asked me to read the first draft. It was the most indiscreet 
and outspoken document I ever read. I hastened to return 


it as quickly as possible, for if by any accident it had come 
into possession of anyone connected with the Press the 
fat would have been in the fire with a vengeance. Some 
of his reminiscences were published afterwards in The 
Times, but these must have been rewritten or very severely 
edited, for they were “ but as water imto wine” compared 
with the draft I saw. I may say that the account he gave 
of his reasons for leaving the Admiralty was practically 
the same as that also pubHshed later in The Times by Mr 
Churchill, the other party concerned in the affair. He told 
me also of an incident which had occurred when he was 
made First Sea Lord. He said Mr Asquith, when making 
up bis Cabinet, sent for him and said, “ ‘ Sir John, your 
name has been mentioned to me for the Admiralty and 
nothing personally would give me greater pleasure, but 
I am in this difficulty : I am hoping to get Mr McKenna 
as my Chancellor of the Exchequer, and I am told that 
you and he are not on speaking terms I said, ‘ Mr 
Asquith, I don’t know why anyone should have told you 
that ; it is quite untrue. I never refuse to be on speaking 
terms with anybody ; you lose so many opportunities of 
saying disagreeable things.’ ” I had occasionally to go 
with Lord Fisher to the Treasury to apply to the Chancellor 
for financial assistance for the B.I.R., and the relations 
between them were most cordial, nay, even jovial. 

Lord Fisher had had some training in science, for when 
a young man he had been an instructor in the Navy and 
given lectures on elementary physics : he told me that 
he always tried to make them as lively and amusing as 
possible. If his lectures were like his talk they certainly 
would be amusing, for he could introduce an un- 
expected word widi great effect: e,g. he had received 
a great number of orders and decorations from foreign 



courts when travelling with King Edward. “ You should 
see me he said, “ when I have got them all on ; I look 
like a blooming Christmas-tree.” Again, I once heard him 
say, “ I cannot understand why X, who is a man of first- 
rate abihty and has done good work, has never received 
any of&cial recognition : some say it is because he has a 
wife in every port and never goes to bed sober ; but trifles 
like that won’t explain it 

He seemed to require much less sleep than most people. 
A naval ofiicer who had been with him a great deal said 
that in his prime he never took more than four hours’ 
sleep, even in his busiest times. I always got on very well 
with him, and his grandson’s name was entered for ad- 
mission to Trinity College when he was only two years 

The experience we had at the B.I.R. showed the 
danger of leaving the investigation of the apphcations of 
science until war breaks out, trusting to being able to 
improvise some makeshift on the spur of the moment. 
The transition from the laboratory to the workshop or to 
the ship is one that m most cases takes a long time and 
much work and expense. Effects which are of trivial im- 
portance in the small-scale experiments in the laboratory, 
may be vital on the large scale necessary for practical 
utility. Faraday said of his discovery of the phenomenon 
of electromagnetic induction that it was a babe, and no 
one could say what it might do when it grew to manhood ; 
but it took more than thirty years for it to pass from the 
nursery of the laboratory to the rough-and-tumble of 
the workshop. Again, electric waves produced in one 
room of a laboratory could be detected in another ten 
years before they could be detected at what now seems 
the insignificant distance of a mile. For this reason the 


B.LR. got the Government to establish a laboratory for 
research on problems which, like that of the detection of 
submarines, might be of service to the Navy. The 
laboratory is at Tedding ton, near the National Physical 
Laboratory. The first director was Mr, now Sir, F. E. 
Smith, who was succeeded by C. S. Wright, an Antarctic 
explorer, who is an old pupil of mine. 

My experience at the B.LR. brought home to me how 
intense and widespread was the eagerness of men of science 
to do something to help to win the war. Many problems 
came before us on which it was important to get expert 
opinion from physicists, chemists, engineers and mathe- 
maticians. These frequently involved special investigations, 
experimental or mathematical, and those who undertook 
them had to put their own work aside. So far from 
grudging this, they welcomed the opportunity of doing the 
war work. We had many appeals for work of this kind 
from those who had not had such work assigned to them. 
Again, men who were engaged in great industries made 
arrangements which enabled them to devote a great deal 
of time to war work. 

A conspicuous example was Richard Threlfall, later 
Sir Richard ThrelfaU. He had given up his Professor- 
ship at Sydney some time before, and had become a 
member of the firm Albright & Wilson of Oldbury, 
near Birmingham, the largest manufacturers of phos- 
phorus in the country, and probably knew more 
than anyone else in England about phosphorus. He 
applied this knowledge with great success to war purposes 
and, through him, phosphorus played a considerable part 
in the war. It was used for making smoke screens behind 
which a vessel could hide from an enemy ship. His 
phosphorus bombs, too, proved very useful. He was also 


the first to suggest the use of helium in place of hydrogen 
for airships. Helium is not inflammable and does not 
explode, and so is a complete safeguard against fire. An 
airship requires, however, a very large quantity of helium, 
and at that time there were no appreciable supplies in our 
Empire. He brought this matter before the B.I.R. and at 
his instigation we got J. C. McLennan, Professor of Physics 
at the University of Toronto, an old pupil of mine, to 
analyse the gases which gush out from the ground in some 
parts of Canada where there are oil wells, and which are 
used to light some towns, e.g. Medicine Hat. Similar gas 
streams in Texas had been found to be rich in helium. 
McLennan threw himself into this work with characteristic 
energy, and examined a large number of the wells in 
Ontario, Alberta and British Columbia. The best results 
were given by a well in the Bow River district in Ontario, 
where there was about 3 parts of helium in 1000 parts of 
the gas coming out of the earth. This, though much 
smaller than that for the Texas wells, is much larger than 
any known in other parts of our Empire. 

Threlfall was a chemist and engineer as well as a 
physicist, so that his services were in continual request 
for reports on projects submitted to the B.I.R. , and there 
were few meetings of the B.I.R. when we had not 
something from him before us. Sir George Beflby 
and Sir Charles Parsons were, hke Threlfall, responsible 
for large concerns and, like him, spared a great deal 
of time for war work. After the war and quite in- 
dependently, indeed for some time unaware that the 
other was doing it, both Parsons and Threlfall made 
experiments on an engineering scale to see if they 
could make diamonds from carbon. The great French 
chemist, Moissan, thought he had done this. He had 

recollections and reflections 

obtained small particles which, though they did not look 
like diamonds, did not behave like pieces of graphite, the 
other form of carbon. The experiments went on for 
about two years and were very costly. Threlfall, after he 
had made up his mind what he had got by his method, 
happened to meet Parsons and said, “ Parsons, I don’t 
mind telling you that my diamonds are graphite “ So 
are mine said Parsons. I beheve the general opinion is 
that Moissan’s must have been so too. 

In addition to my work at the B.I.R. I was, for the 
greater part of the war, Chairman of a Government Com- 
mittee to report on the position of natural science in the 
educational system of Great Britain. This was very in- 
teresting though it involved attendance at a great many 
meetings. We examined a large number of witnesses and 
produced a report which was signed by all the members of 
the Committee. In the report it stated that it could now 
be claimed that some science is taught in all schools and a 
great deal in a great many. This is a great advance and 
has practically aU been made in the last fifty years. It 
cannot, however, be said that even now science occupies 
in our system of education a place commensurate with its 
influence on human thought and on the progress of civili- 
sation.” We pointed out in our report that the examina- 
tion for entrance scholarships to our great pubHc schools 
tends to entice boys to classics whose strength may lie in 
other subjects. In the examination for these scholarships 
much greater weight is given to classics than to any other 
subject, and a boy must have spent most of his time on 
classics if he is to have a chance for a scholarship. Thus 
when he goes to school he is much further advanced in 
classics than in anything else, and naturally takes it as his 
main subject. That this is the case is proved by the fact 


that, of the entrance scholarships to Cambridge Colleges 
gained by boys from seven great public schools which give 
school entrance scholarships, for one gained for science six 
were gained for classics , This disproportion is far greater than 
the average for all schools, showing that it is not due to the 
scarcity of scientific abihty as compared with classical, but is 
an artificial one due to the system in force at these schools. 

Another matter which came before the Committee 
was the intense speciahsation adopted by some schools in 
the preparation of boys for entrance scholarships given by 
Cambridge and Oxford Colleges. We were told of cases 
where such boys spent by far the greater part of their 
time, for two years before the examination, in doing the 
mathematical papers which had been set in previous years. 
I think, however, that this mainly occurs in small schools 
where it is rare to have a boy of anything like scholarship 
standard. When there is one, the master not unnaturally 
wishes to make the most of him, so as to raise the reputation 
of the school. 

Another question the Committee considered was that 
of the age for leaving school. This was not then, as it is 
now, compHcated by its connection with the rehef of un- 
employment. The evidence which came before us showed 
that, though an extra year was unpopular with a large num- 
ber of parents on the ground that they would lose the wages 
which their boys might have earned if they had left school, 
it was much more unpopular with the boys themselves, 
who for the most part wanted to be their “ owm masters 
as soon as possible, and thought it more manly to be an 
errand-boy than to be at school. There were, however, 
many boys, and some of them by no means the least in- 
telligent, who were fed-up with school, took no interest 
in their work, and if they stayed longer at school would be 

225 Q 


only marking-time until they could get away. Some of 
these were boys whose minds, like those of very many of 
their elders, do not exert their full powers until they have 
some concrete problems to deal with. Then they may 
show more abihty than those who have done better at the 
bookish subjects and got higher up in the school. I feel 
convinced that the best subjects for developing a boy’s 
intelligence are diose in which he is interested, and if he 
cannot find these in his school work, I think it is better 
he should leave school and see whether he cannot find them 
in business, or in the workshop or the miU. I have seen at 
the Cavendish Laboratory instances of a great increase in 
intelligence after leaving school and coming to work as 
laboratory assistants. I have knovm cases where a boy, 
who did not seem very promising when he first came to 
the Laboratory, at the end of the year showed a decided 
increase in intelHgence. This increase went on until he 
became a very efficient assistant either for research or for 
lectures, or a very capable foreman in the workshop. It 
is remarkable that, though the Engfish are not a specially 
bookish people, there are many who seem to think that it 
is only in the study of books that intellect is exerted, in 
spite of Dr. Johnson’s dictum that in the study of history all 
the higher quafities of the mind are quiescent. The great 
German man of science, von Helmholtz, who, beginning 
as a medical student, was led by his medical studies to study 
physiology, by his physiology to study physics, by his 
physics to study mathematics, and rose to be one of the 
foremost authorities of his time in all these sciences, 
declared that he had spent more intellectual effort in get- 
ting an instrument that was out of order to work properly, 
than he had in framing the theory which the instrument 
was being used to test. 



Science teaching in schools has had many difficulties 
to overcome. Laboratories for physics, chemistry or 
biology are generally expensive, and may put a severe 
strain on the resources of those schools which are not in 
receipt of a Government grant. It is not, however, neces- 
sary, perhaps not even desirable, that school laboratories 
should be equipped with very elaborate and expensive 
instruments. An enthusiastic teacher may get excellent 
results with simple and even with improvised apparatus, 
just as great discoveries have been made by physicists work- 
ing in their own houses. Indeed, simple apparatus is more 
intelligible to the student than elaborate instruments where 
the physics of the experiment may be hidden by the com- 
plexity of the instrument. It is necessary, however, that 
the instrument, though simple, should be designed so as to 
be capable of giving accurate results. 

Another, though less important, point is that while the 
teaching of classics and mathematics has a long experi- 
ence and tradition behind it, the teaching of science in 
schools has no such tradition, and its methods have had 
to be developed. I think too much importance may be 
attached to the consideration of method. The personality 
of the teacher is the most important thing ; a good teacher 
will soon find the method which in his hands will give the 
best results, and will do better with this than with one 
imposed on him from without. 

I was, during the greater part of the war, President of the 
Royal Society, and for the last eight months of it Master of 
Trinity College. Though the work of the President of the 
Royal Society was not quite so arduous as it is in normal 
times, when he is expected as the representative of British 
science to attend a large number of public dinners which, 
especially when he is not Hving in London, take up a good 



deal of his time, I had with it, the B.LR. and the Committee 
on Education, plenty to do, and spent the greater part 
of my time in London, generally, however, coming back 
to Cambridge in the evening, as I foimd its quiet refreshing 
after the turmoil of that city. One night, however, after 
a very long day’s work, I stayed in London at Garland’s 
Hotel in Suffolk Street. After I had gone to sleep I was 
awakened by a prodigious noise, which turned out to have 
been due to a bomb which fell close to the hotel. I soon 
fell asleep again and slept until breakfast-time. When I 
came down I found I was the only person who had not 
spent the night in the basement. The Zeppelin had returned 
not long after it had dropped the first bomb and dropped 
several other bombs as it came back, without awakening 

Cambridge during the War 

With the breaking out of the war in August 1914 
there began a period lasting for more than four years when 
everyone had to give up his usual work and turn to some- 
thing which might help to enable us to win the war. 
Those undergraduates who were physically fit joined the 
Army, taking at first commissions in the Regular Army, 
and later in Kitchener’s. The older men helped with the 
work in Government offices, e.g. the Foreign Office and 
the Admiralty. Some who had an especially intimate 
knowledge of some foreign language, or were adepts at 
acrostics or cryptograms, joined the department which 
was estabhshed for decoding the German wireless messages; 
others went as masters in schools to firee a younger man 
for service in the Army. Some of those who remained 
in Cambridge undertook to patrol the streets at night to 


see that all lights were out, as it was thought very important 
to make it as difficult as possible for the Zeppelins to locate 
Cambridge. In this they were very successful, as Cam- 
bridge was never bombed in the war, though bombs fell 
within a few miles. It was so dark at night that people 
who, like myself, are bad at seeing in the dark, when they 
went out, were continually bumping into people in the 
streets. So vigilant were these inspectors, and none more 
so than the late Dr. McTaggart, the distinguished philo- 
sopher, that Trinity College had to give up using white 
linen table-cloths on the dining-tables in Hall, as it was 
thought that light might be reflected from these through 
the lantern at the top of the Hall. The oak tables looked 
so well "without cloths that these have not been resumed. 

The cloisters of Trinity College very early in the war 
were used for a hospital for some of those wounded in 
the earlier battles. They continued in use until the large 
hospital which was being installed on the King's and 
Clare cricket ground was completed. At first, too, some 
regiments were billeted in one of the courts of the College, 
but for by far the greater part of the time the College was 
filled with young men who had already joined the Army, 
and came to receive an intensive course of instruction, by 
lectures and by physical training, to qualify them to receive 
a commission. Some of them had already been at the 
Front as privates and had shown promise of making 
efficient officers. They were under the charge of a 
military staff. Besides their training, the cadets played 
football and cricket matches, had athletic sports and pub- 
lished an illustrated magazine, The Blunderbuss. This 
will hve in history, as it was in it that Professor Housman, 
who was in residence, first published his well-known poem 



As I gird on for fighting 
My sword upon my thigh, 

I think on old ill fortunes 
Of better men chan 1. 

The cadets attended church parade in the Chapel on 
Sunday mornings, and they adopted Bunyan's hymn — 

He who would valiant be 
’Gainst aU disaster, 

one often sung in our Chapel, as a song to sing when they 
were on the march. At the end of their course they were 
entertained in the College Hall at a farewell dinner. 

Batches of them came to the Lodge on Sunday morn- 
ings after Church parade, and I got an opportunity of 
talking to them. Some of them were remarkably interest- 
ing and intelligent and took a great interest in the buildings 
and pictures in the College. Some who had been at the 
Front were miners, and I was surprised to find the affection 
they had for their mine. They said a mine was such a 
nice place, so warm and comfortable, and they seemed to 
dislike the trenches even more than the others. 

The stay of the cadets at Trinity gave us many pleasant 
reminiscences and went off without a hitch. This was 
due in part to the very friendly relations which existed 
between the military staff and the Fellows of the College, 
and m an even greater degree to the tact and diplomacy 
of the late R. V. Laurence, who took on himself the work 
of the Junior Bursar, who had gone to the Front. Laurence 
conducted many dfficult negotiations with the War Office 
with such tact and skill that a solution was reached which 
was satisfactory to both sides. The loss of Trinity men in 
the war was grievously large : on the panels in the College 
Chapel the names of more than 600 Trinity men who fell 
in the war are inscribed, including three of the younger 


Fellows of the College. Keith Lucas, F.R.S., killed in an 
aeroplane accident, was a College Lecturer in natural 
science, and a man of remarkable abiHty. He had done 
important work in physiology ; he excelled also in design- 
ing instruments for scientific research, and invented an 
internal combustion engine on a novel principle. C. E. 
Stuart was a College Lecturer in classics ; he was killed 
at the Front a few weeks after his marriage. Geoffrey 
Tatham was our Junior Bursar and was much beloved in 
the College. There is a sundial in the College garden in 
memory of these three friends. Tatham left a legacy to 
the College which was used to panel the Combination 
Room now in use, which was made just after the end of 
the war by throwing together some rooms which had 
formerly been a part of the Lodge. It is one of the 
most frequented rooms in the College : in the daytime 
it is the place where numberless committees have their 
meetings, and at night it is where the Feljows take wine 
after HaU. There is an inscription in the room recording 
the legacy and there could be no place more fitted to 
keep his memory green. 

In this list there are the names of many younger men 
who had already distinguished themselves in many walks 
of Hfe, and done enough to show that much might have 
been expected from them. They one and aU have en- 
dowed the College with the precious heritage of being 
able to count among its members so many who have made 
the supreme sacri&ce for their coxmtry. They are bene- 
factors of the College, and it is fitting that the Hst of our 
benefactors, which is read every year at our ammal Com- 
memoration, should conclude 'with this reference to them : 

Lastly, while we thus enumerate those who have enriched 
us of their substance, it behoves us also to commemorate 



those other benefactors, an unnumbered multitude who 
by achievements in Hterature, science, philosophy and the 
arts, or by patient continuance in well-doing have brought 
honour to the House and good report, and more especi^y 
those six hundred fallen in war whose names are written 
on these walls. For it is meet that we should have these 
also in remembrance, celebrating them in our praises and 
having them in honour at such times as these.*’ 

About 16,000 Cambridge men served in the war : of 
these 2652 were hilled, 3460 wounded and 497 reported as 
missing or prisoners ; 12 obtained the Victoria Cross, 
899 the D.S.O. and 5036 were mentioned in dispatches. 

Things were at the worst in the academical year 
1917-18. Only 281 students matriculated ; the number 
of men students had fallen to a fraction of the normal value, 
and since the greater part of the income of the University 
comes from fees, the financial position was very serious. 
The Council of the Senate met throughout the war but 
dealt, with one exception, only with necessary routine 
business. It would evidently have been very unfair to 
bring forward any contentious business, involving as it 
would voting in the Senate House, when the majority of 
the younger members were away on mihtary service and 
unable to register their vote. There was, however, one 
question on which there might be a difference of opinion 
which it was necessary to settle before the war ended, and 
that was for how many terms should the men who had 
been at the Front be required to reside, after their return to 
Cambridge, to qualify them for a degree. It was evident 
that it was only fair that they should not be required to 
reside as long as those who had not been away on service, 
and that whether they returned to Cambridge or not would 
depend on the amount of the reduction. The first proposal 


made by the Council was severely criticised as not being 
generous enough, and the Council withdrew this proposal 
in favour of one which allowed those who had been away 
on service for four or more terms to count four terms as 
residence in the University, and that they should be excused 
from passing the Litde-Go. 

The German victory at St. Quentin in March 1918 gave 
htde hope of a speedy termination of the war, but “ the 
darkest hour is that before the dawn ”, and conditions 
improved very slowly at first but with ever-increasing 
rapidity, and the Armistice was signed in November 1918. 
The Government made liberal grants to help those who 
had served in the war to come back to the University, and 
these did so in great numbers. In January 1919, 655 students, 
and between January and June 1552 students, matricu- 
lated. These numbers include 400 naval officers who came 
to Cambridge to complete their scientific studies, which had 
been interrupted by the war. There were also with us 
for the Easter Term about 200 American soldier students. 
Another instance of the rapidity with which the University 
filled up was that, in Jime 1919, 105 students passed Part I 
of the Mathematical Tripos. The Vice-Chancellor, in his 
address to the University in October 1920, reported that 
the University was full to overflowing. In June 1919 the 
University decided, by 161 votes to 15, that Greek should 
no longer be compulsory for the Little-Go. This ended a 
controversy which had been smouldering and occasionally 
bursting out for more than thirty years. 

The war had lasted for more than four years, which is a 
year longer thananxmdergraduate’s stay in College, and we 
were afraid that there might be no one to hand down the 
traditional conventions, to restart the clubs and other forms 
of undergraduate activity. This fear, however, proved 



baseless : though these students had gone through the grim 
experiences of the war and were older than the pre-war 
undergraduates, it was surprising to see how like their ways 
were in most things. They talked very httle about the 
war ; they seemed almost to wish to blot it out of their 
lives, and to have just the same experiences as those who 
came before them. There was no breach of continuity, 
in fact hardly a bump in the crossing from war to post-war 
times. As the boat race takes place in March and no one 
had returned until the middle of January there was no time 
to make preparations, but the cricket match with Oxford, 
which is not played until July, came off. 

The cessation of the war relieved us from much anguish 
and anxiety and raised great hopes : we thought that, as we 
had weathered the storm, the rest would be comparatively 
plain sailing to prosperity greater than the nation had ever 
had before. These hopes have certainly not been fulfilled. 
I think, too, there has been a considerable change in the 
views about war held by not a few of the younger men. 
In the war there were in the University some conscientious 
objectors, but not very many ; several of these were 
Quakers, and the greater number objected to war on reH- 
gious grounds. There were very few whose sincerity could 
be questioned ; indeed it required great moral courage, 
or exceptional physical cowardice, to face the odium of 
being a conscientious objector rather than go to the Front. 
I think in another war the conscientious objector will be 
a much more serious difficulty than he was in the last : 
there will be many who would fight to defend their 
country if it were attacked, but who would not go into 
another country and attack it. It is, however, difficult in 
warfare to rely on defence alone for repe llin g an attack. 

My only brother died before the end of the war. He 



was the most unselfish of men and devoted most of his free 
time to the Hugh Oldham Lads’ Club in Ancoats, Man- 
chester, of which he was Honorary Secretary for 21 years. 
This Club is connected with the Manchester Grammar 
School, and Ancoats was then one of the most slummy 
districts in Manchester. My brother, who was a bachelor, 
was engaged all day in business, but used to spend regularly 
four evenings a week at the Club. He was a great lover 
of boys and very successful in his dealings with them. 
His method was very simple ; he never gave lectures or 
made speeches, but just talked with the boys one by one. 
Above all, the boys always knew where they could find 
him if they were in any difficulty and wanted his help. 
Playing-fields near Manchester could not be got except at 
very considerable expense, and the Club had to be content 
with derelict pieces of land on which “ soccer ” could be 
played after a fashion, though cricket was impossible. 
In games which did not require playing-fields the Club was 
very successful. Open championships in long-distance 
races, both swimming and nmning, were won by boys 
who had been at the Club, where their swimming had 
been done in municipal baths, and their running by racing 
through the streets of Manchester at night. As these long 
races require special powers of endurance, this shows 
that even the slums of a large town may produce boys of 
as good physique as any in the country. My brother was 
very fond of chess, and he managed to impart his fondness 
for it to a good many of his boys at the Club. A great 
event in the Club life was the annual camp, when the boys 
camped out for a week in the country or at the seaside. 
The preparation for the housing, feeding, entertaining and 
providing for the many contingencies which were likely 
to arise, for a camp of five or six hundred boys, was a very 



formidable business; it involved dealing with number- 
less details and required heavy work lasting over a long 
time. My brother had as long and as successful experience 
of this work as anyone, and was often consulted by Boys’ 
Clubs who proposed starting a camp. He told me what 
I should not have expected, that the boys enjoyed the 
camp most when there was a town of considerable size 
within easy reach; aftqr two or three days in the country 
they began to miss the bustle and shops and other attrac- 
tions of the town. If they could go into a town for an 
hour or two this longing was cured, and they came back 
eager again for the camp life. He very often had the camp 
at Prestatyn, a place on the Welsh coast near to Rhyl, a town 
which acted as a tonic. I heard of another case which 
also showed this nostalgia for the town in town boys. A 
man interested in boys’ welfare took two London boys for 
a trip to the Canadian Rockies. When they first saw the 
snow mountains he said, “ Did you ever see anything like 
this before ? Isn’t it magnificent ? ” One boy said, “ It 
may be all very well for them as hkes it, but give me 
London on a Saturday night 

My brother’s health broke down in 1914 and he had 
to give up his work at the Club. He came to live at 
Cambridge and spent much time in writing letters to boys 
at the Front who had been at the Club . He also came across 
some Cambridge boys he was able to befriend. He died 
on July II, 1917. 

I lost during the war an old friend, Sir W. D. Niven, 
F.R.S., who had been very kind and helpful to me ever 
since I was a freshman at Trinity. 

Lord Rayleigh, the Chancellor of the University, died 
at his home, Terhng Place, Essex, on June 30, 1919. He 
had not been in good health for above a year, but was well 


enough to deliver his Presidential Address to the Psychical 
Society, of which he was President and had been a member 
for 22 years, in April 1919* The funeral was at Terling and the 
University sent a deputation headed by the Vice-Chancellor. 

Lord Rayleigh had been elected Chancellor in succes- 
sion to the Duke of Devonshire in 1908. He had some 
hesitation about standing because, with one exception (the 
Marquis of Camden), there had been no Chancellor for 
over two hundred years who had not been a Duke at least. 
Curiously enough Mr Arthur Balfour, who succeeded him, 
felt scruples about allowing his name to be put before the 
University for the Chancellorship because no commoner 
had ever held that office. Lord Rayleigh was elected 
Chancellor without opposition. The installation was on 
June 17 ; he came up to Cambridge on the i6th and opened 
in the afternoon a new wing of the Cavendish whose 
erection was made possible by the donation o£ ^2000 which 
he had made to the University when he received the Nobel 
Prize. For five years he had come to the Laboratory 
almost daily in term time, but he had never before come 
to it in a scarlet gown with two esquire bedells before him, 
carrying their long silver maces, head downwards. These 
maces, though they bow their heads before the Chancellor, 
disdain to do so before a mere Vice-Chancellor, and are 
then carried with their heads uppermost. 

After the installation on the 17th, the new Chancellor 
conferred honorary degrees on a number of distinguished 
people. It is the custom for the Chancellor himself to 
nominate the recipients of the degrees given at his installa- 
tion. Mr Asquith, the Duke of Northumberland, the 
Earl of Halsbury, Admiral Sir John Fisher, Sir H. von 
Herkomer, the Hon. C. A. Parsons, Sir G. O. Trevelyan, 
Bart., Sir James Ramsay, Bart., Sir W. Crookes, Mr Rud- 


yard Kipling, Mr Alfred Marshall, Professor G. D. Liveing 
were the recipients of degrees. At the luncheon after the 
conferring of degrees. Sir Andrew Noble announced that 
some of Lord Rayleigh’s friends, not resident in Cambridge, 
wished to express the gratification of the scientific world 
at his election by offering to the University a sum sufEcient 
to provide an annual prize to bear his name. The Rayleigh 
Prize for mathematics was founded with this donation and 
is awarded at the same time, and by the same Electors, as 
the Smith’s Prizes. Sir H. von Herkomer, to express his 
appreciation of the degree he had received, presented to the 
University a portrait by himself of Lord Rayleigh in his 
Chancellor’s robes, which isnow in the Fitzwilliam Museum. 

Lord Rayleigh told me that the one thing he regretted 
about his election was that the presence of the Chancellor 
in Cambridge interfered so much with the ordinary busi- 
ness of the University, and gave so much trouble, that he 
was afraid he ought not to come to Cambridge as often as 
he had done before. I said I was sure that if he came on 
unoJSicial visits the University would respect his privacy, 
and that they would wish to make the duties as htde 
burdensome as possible, and would not expect him to come 
to Cambridge except on important occasions. As far, 
however, as I can remember, he never came to Cambridge 
except on official visits. He came and dehvered an address 
for the Darwin Celebration in 1909 ; to confer honorary 
degrees in 1911, and in 1912 on two occasions, one to confer 
honorary degrees, and the other to receive the International 
Congress of Mathematicians ; he came in June 1914 for 
the opening by Prince Arthur of Connaught of the new 
physiological laboratory given by the Mercers’ Company. 
This was his last visit to Cambridge as there were no 
ceremonial functions during the war. 



Though Rayleigh held and adorned other offices besides 
the Chancellorship, his official work was not comparable 
in importance with his scientific, which was quite out- 
standing both in magnitude and importance. This is not 
the place to describe it in detail, but it cannot be passed over, 
though all I can give is an appreciation of it in the most 
general terms and an indication of what seem to me to be 
some of its characteristics . In addition to his standard Theory 
of Sound in two volumes, there are 445 papers in the 
Scientific Papers of Lord Rayleigh, published by the Cam- 
bridge University Press. These cover a very wide range : 
besides papers on pure mathematics, there are some on 
general mechanics, elastic solids, capillarity, hydrodynamics, 
sound, thermodynamics, dynamical theory of gases, pro- 
perties of gases, electricity and magnetism, optics ; practi- 
cally on every branch of physics known when he began his 
scientific work. Not a few of these, such as those on the 
determination of the electrical units and on the discovery of 
argon, had involved years of work in the laboratory, and 
others long mathematical calculation. While most collec- 
tions of scientific papers rest undisturbed on their shelves, 
and are monuments, rather than parts of one’s working 
Hbrary, there are no books I refer to so frequently as 
Rayleigh’s collected papers . His papers deserve the descrip- 
tion, which Maxwell appHed to those of Ampere, as being 
“ perfect in form and unassailable in accuracy ”. The 
style is very clear, so clear in fact that the reader may not 
realise how difficult the problem was tinless he has attacked 
it himself before reading the paper. It is also very concise, 
and somewhat austere ; there are no frills. It must have 
been umate, for one of his examiners in the Mathematical 
Tripos said some of his answers to the questions might 
have been sent to Press without any revision. A quahty 



which can be retained in the turmoil of that examination 
must be deeply ingrained. 

Rayleigh possessed to a very remarkable extent the 
power of putting his finger on the really vital point of a 
question. He was therefore able to simplify the solution 
by taking a case where, though this point had not been 
affected, everything else which only increased the mathe- 
matical difficulties had been stripped off, and the mathemati- 
cal difficulties reduced so much that a solution was possible. 
The same thing appeared m his experimental work. In 
the apparatus the part which really affected the accuracy 
of the results was sure to be all right and carefully made, 
while the other parts might be made up of bits of sealing- 
wax, string and glass tubes. Another quahty for which 
he was remarkable was soundness of judgment on physical 
questions. In this among all the men I ever met he was 
only rivalled by Stokes, a man of much the same type of 
mind. It was not easy to get an opinion from either of 
them if you consulted them about some new idea m 
physics ; they would not commit themselves unless it 
affected some question to which they had given a great deal 
of thought, but when it did come it was well worth having. 
I owe a great deal to the talks I have had with them. 
There was no difficulty or delay in getting an opinion from 
Lord Kelvin but it was always adverse to the idea. Ray- 
leigh shared Maxwell's and Kelvin's view of the import- 
ance of models as an aid to physical discoveries. He says, 
“ There can be no doubt, I think, of the value of such 
illustrations both as helping the mind to a more vivid 
conception of what takes place, and to a rough quantitative 
result, which is often of more value from a physical point 
of view than the most elaborate mathematical analyses 
The establishment of the National Physical Laboratory 


owes much to the influence he exerted in its favour : he 
took a very keen interest in its progress, and presided over 
the executive committee until shortly before his death. 
He was President of the Advisory Committee on Aero- 
nautics from its institution in 1909 imtil his death in 1919. 
During the war his advice was often asked by the various 
Government Committees engaged on war work, especially 
on questions which involved difficult points in hydro- 
dynamics or acoustics. In addition to his scientific attain- 
ments he was a most agreeable companion, human enough 
to have a store of good stories which he liked telling. 
Some of these are given at the end of the excellent bio- 
graphy by his son. 

On March 5, 1918 , 1 was admitted to the Mastership of 
Trinity College. Trinity is the only College in Cambridge 
whose Master is appointed by the Crown, and the ritual 
for his admission to the Mastership differs from that in 
other Colleges, where the Master is elected by the Fellows. 
On the day of admission all the gates of the College were 
closed early in the morning, and no one was admitted to 
the College without special permission. At 12 o^clock I 
arrived at the Great Gate in academical costume, but 
wearing my hood “ squared ”, the way it is worn by the 
Proctors, which makes it look very different from the 
normal hood. The gate was locked and I gave three or 
four hard knocks at the wicket-gate ; this was opened a 
few inches by the Head Porter (who had been my gyp 
when I hved in College), who asked who I was and what I 
wanted. I told him my name, and gave him the Patent 
of my appointment, and asked him to take it to the 
Fellows. He took it, and then closed the door again, and I 
waited outside and afforded amusement to a crowd which 
had assembled in the street. After a very few minutes the 



Great Gate was thrown open, and the Vice-Master (Dr. 
Jackson), who was at the head of a procession of Fellows 
that had waited in the Ante-Chapel, came forward, 
shook me by the hand and presented me to the Fellows, 
A procession was formed to the Chapel, with the Vice- 
Master on the right and I on the left, and the other Fellows 
following iri order of seniority. No one had been admitted 
to the Chapel and the doors were locked. The Patent of 
Appointment was then read, and I made the declaration 
which the Statutes of the College require before a Master 
can be admitted. I was then admitted to the Mastership 
by the Vice-Master, took my seat in the Master’s Stall and 
the choir sang the Te Deum. I was then escorted by the 
Fellows to the doors of the Lodge. Owing to the war 
there were hardly any undergraduates in the Court ; 
these were replaced by cadets of the Officers’ Training 
Corps, who turned out in force ; there were some hundreds 
of them hving in Trinity at the time. There was a dinner 
for members of the College in the evening, when the 
Vice-Master proposed my health and I replied. 


SIR J. J. THOMSON ; circa 1922 


Visit to America in ig 23 

I WAS invited by the Franklin Institute of Philadelphia 
to give a course of lectures there in the spring of 1923, 
and for that purpose my daughter and I sailed in the 
Majestic in April of that year. The Majestic, which had 
been before the war a German vessel, was taken over when 
the war ended ; she was at that time, I beheve, the largest 
liner afloat. We had not particularly fine weather, but 
there were some very agreeable people aboard, and we 
enjoyed the voyage. It was not, however, very nautical, 
for we saw a great many waiters and very few sailors. 
The incident I remember most vividly was the arrival of 
the news, a few minutes after the race had ended, that 
Oxford had won the boat race ; this was not expected 
and has not occurred again. 

On arriving at New York we found the Secretary of 
the Franklin Institute, Mr R. Owens, an old pupil of mine, 
waiting to welcome us ; he took us at once to one of the 
largest and most deHghtfuUy situated hotels in the city ; 
this was the beginning of a boundless and most charming 
hospitahty, which made my visit one of the most dehght- 
ful episodes in my life. We stayed a few days in New 
York before going on to Philadelphia. I was very much 
impressed by the change in New York since my last visit 
some fifteen years before. There were so many new 
buildings that it seemed to be a new city and one of great 
beauty and dignity. The sky-scrapers were very much 



more plentiful and very much higher than before, and this, 
to my mind, was all to the good. I have always admired 
sky-scrapers and think that they are the greatest contribution 
of our generation to architecture. I remember very well 
the first of these, the old “ flat-iron ’’ building in New 
York. I once saw it in a mist thick enough to obscure the 
surrounding buddings, and it looked like the bows of a 
great vessel coming out of nowhere and bearing down on 
a doomed city. America must have been fortunate enough 
to possess great architects to create, and make so effective, 
this new type of building. 

Broadway, too, had become, I will not say more beauti- 
ful, but certainly more effective, in its special mission of 
forcing itself upon one’s attention. The luminous adver- 
tisements were so numerous that each side of the street 
seemed to be ablaze. Piccadilly Circus at its best or worst 
is to Broadway but as moonlight is to sunhght. 

Mr Eglin, a Vice-President of the Franklin Institute, 
whose kindness in thinking of and providing everything 
that would add to our pleasure, interest or comfort was 
one of the main reasons why our visit was so pleasant, 
invited us one night to dine with him at the Ambassadors 
Restaurant, and took us after dinner to the Ziegfeld Follies, 
the most famous theatre in New Y ork. W e saw there Will 
Rogers, whose tragic death in an Arctic aeroplane accident 
occurred ordy a fortnight before I am writing this. His 
performance was quite unlike anything I ever saw, before 
or since. He had been a cowboy, and in his spare time 
had practised doing tricks with his rope. In one of his 
turns at the Follies, he stood holding one end of a rope in 
his hand and making it go into all kinds of curves ; while 
he was doing this, he jerked out one short sentence after 
another about some pohtical, social, or indeed any kind 


of event that was in the papers at the time ; most of them 
were about things I had not heard of, but I found some of 
the others not only excruciatingly funny, but also very 
sensible. I should think they were quite Hkely to have 
considerable effect on poHtics. Some of his criticisms 
were very shrewd, and so humorous that they would stick 
in people’s memories after political speeches or news- 
paper articles had been forgotten. 

The next day I visited Mr CofSn, who was then Presi- 
dent of the General Electric Company, at his home in 
Long Island ; he had a beautiful and very large garden 
and woodlands in which he took a great interest. It was 
too early in the year for flowers out of doors, but there 
were plenty in the greenhouses. For some time an epi- 
demic among chestnut trees had been raging and he had 
lost more than a thousand trees ; he showed us some of the 
planks which had been sawn from them, and they were 
riddled with holes more than a millimetre in diameter. 
Mr Coffin took me to have lunch at the Country Club 
near by. ‘‘ Country clubs ” are a great institution in 
America, and are to be found near most cities, but I never 
saw one nearly so luxurious as this ; it had a magnificent 
club-house, a polo ground with stables, many lawn-tennis 
grounds, a swimming-pool, and a golf-club where the 
annual subscription must, I should think, be a record. I 
was told that even to get on the waiting-list you had to 
subscribe for a substantial amount of the debentures issued 
by the club ; some of the envious critics declared that the 
number of strokes taken by some of the members to get 
round the course was as stupendous as the subscription. 
Mr Coffin had very vtide interests : they included etchings, 
of which he had a very fine collection. 

During my stay in New York I visited some works where 


they were operating a new process for moulding sheets of 
aluminium into many different shapes. It consisted in passing 
an enormous current of electricity through the sheet for a 
very minute fraction of a second ; the current was so great 
that even in this short time the sheet became plastic and 
could be moulded by pressure. The process was most 
interesting as a triumph of electrical engineering. The 
enormous current was got by short circuiting through the 
plate the terminals bringing the electric Ught supply into 
the works. So perfect were the arrangements that there 
was no sparking when this huge current was broken and 
not a trace of flicker in the electric lamps in the building. 

We spent the week-end after our arrival in New York 
with our friends in Baltimore. I was glad to find that 
Johns Hopkins University had had some share of the pro- 
sperity which the other universities had enjoyed, and had 
been able to erect much larger and better equipped btuld- 
ings in the outskirts of the town. My old friend Professor 
Ames was now the President of the University. Professor 
R. W. Wood, the well-known physicist, the maker of 
many important discoveries and the author of a very 
valuable textbook on Light, was Professor of Physics, 
Professor Wood has written books in a Hghter vein than 
the one on Light; his How to tell the Birds from the Flowers 
does not require any previous knowledge of ornithology 
or botany : it is very amusing and has had a very large 

After a very pleasant week-end I left on the Tuesday 
morning to go to Philadelphia for my lectures, visiting 
several universities on my way. I travelled for the rest 
of my j oumey in almost regal splendour. My kind fnends 
at the Franklin Institute had placed at my disposal a private 
train. It had a dining-room, a parlour, two bedrooms, a 


kitchen, a cook, a waiter, and a conductor in charge of the 
train. I had to travel about a good deal for the rest of my 
visit, as I had promised to lecture at several universities. 
All I had to do was to tell the conductor, before I went to 
bed, where I had to be the next morning and what I would 
like for my breakfast. When I awoke, I found I was at my 
destination and the breakfast was ready. In this way I 
revisited Harvard, Princeton and Yale, lecturing at each of 
them and assisting at the opening of a mag nifi cent new 
chemical laboratory at Yale. I had the great pleasure of 
meeting many old pupils and old friends, as well as meeting 
many interesting people for the first time. It was also 
most satisfactory to find the great strides that had been made 
in these universities since my last visit ; in each one of 
them there were many new laboratories — ^large and well 
equipped ; very many new Professorships had been founded 
and many more opportunities for advanced study and 
research made available. Above all, they seemed to be 
inspired with a genuine enthusiasm for research. The 
large number of discoveries in Physics and Chemistry of 
first-rate importance made in the United States during the 
last ten years proves that fuU advantage has been taken of 
these increased opportunities. 

I visited also the research laboratory of the General 
Electric Company at Schenectady ; visits to this are al- 
ways enjoyable, as you are sure to find that the distin- 
guished physicists there have something new and interest- 
ing to show you. This time they had just succeeded in 
making a talking film that would work. They took a 
film of me while I was saying a “ few words I suppose 
I must have been one of the first to take a part in a talkie 
film. The researches of the scientific staff of the General 
Electric Company, Dr. Langmuir, Dr. Coolidge, jMrDush- 


man, have led not merely to results of outstanding in- 
dustrial importance, but also to discoveries, methods of 
investigation, and instruments, which have greatly advanced 
our knowledge of physics. 

I visited, too, the research laboratories of the Bell 
Telephone Company, a vast and wealthy Corporation, 
which has magnificent laboratories and a large staff of able 
physicists. I saw there some most interesting experiments 
on the effect of taking out of the human voice sounds of 
different pitch. They had filters which would take a 
note of a particular pitch out of any sounds that passed 
through them ; by using a number of filters absorbing 
notes of different pitches they could find what effect with- 
drawal of any particular note had upon the voice. They 
showed me experiments in which all the notes within 
considerable range of pitches were taken out of a 
voice without markedly altering its character, certainly 
not nearly enough to prevent one recognising the speaker 
by his voice. 

I think that the research laboratory of a single company 
is more likely to be successful than one under the control 
of a combination of companies. The pecuniary induce- 
ments are greater; the management is likely to be better too, 
since an individual is better than a committee for work of 
this kind. Then they can choose a problem in which they 
are particularly interested, when they know the defects 
of the existing method, its inefiSciency, its uncertainty, its 
cost and so on, and they want to find a method which is 
free from them. Take, for example, the tubes for pro- 
ducing X-rays ; these require the production of cathode 
rays. In the old method these were produced from the 
gas in the tube. This gas produced great irregularities ; 
the discharge caused the gas to be absorbed by the walls of 


the tube, until the pressure was too low to allow the dis- 
charge to go through the tube. It was evident that a great 
improvement would be made if the gas were eliminated. 
The problem was solved by Coohdge, who got his elec- 
trons to produce the cathode rays by heating a tungsten 
jSlament to a very high temperature, when, as was known, 
it emits a copious stream of electrons. A firm which had 
been interested in the production of the old form would 
have developed a technique in the manipulation of the tube, 
in the glass-blowing and the insertion of electrodes, which 
would make the investigation of different methods for 
improving the tube much easier for them than for anyone 
attempting the problem without this experience. 

I reached Philadelphia, where my lectures were to be 
given, on April 9, and found rooms provided for me in the 
Bellevue Stratford Hotel. Philadelphia is one of the most 
important cities in America and is a great centre of busi- 
ness and finance. To the physicist it has another attrac- 
tion which it can never lose ; it was the cradle of American 
science. It is where, in the middle of the eighteenth cen- 
tury, Franklin made researches which will connect its 
name for ever with electricity. Benjamin Franklin was 
one of the most remarkable men that America or any other 
country has ever produced ; his activities and successes 
covered as varied a field as those of Francis Bacon himself. 
He was not bom in Philadelphia, the city with which he is 
always associated, but at Boston, New England, in 1706. 
When he was seventeen he ran away from Boston, where 
he had been apprenticed to his brother, who was a printer, 
and arrived at Philadelphia nearly penniless. However, 
he soon got employment in a printing office there, and it 
was not long before he started as a printer on his own 
account and was very successful. He was almost self- 


educated, for lie left school when he was ten. He took 
great pains to learn to write English. The method he 
adopted was to read an article in the Spectator, and then, 
after he had forgotten the words but still remembered 
the substance, try to rewrite the article. The method was 
very successful in his case, for he acquired the power of 
writing singularly clear and vigorous English, and became 
a remarkably effective pamphleteer. He said himself that 
his power of being inteUigible was one of the main causes 
of his success. For more than twenty years he pubhshed 
Poor Richard's Almanac, which, besides the usual contents of 
almanacs, contained a collection of snippets of worldly 
wisdom such as A penny saved is a penny gained 
The circulation of this increased to 10,000 — far, far greater 
than that of any other publication in the country. 

It was through the discovery of the Leyden jar in 1745 
that Franklin’s attention was turned to electricity. This 
jar made it possible to collect far larger quantities of elec- 
tricity than had been obtained before, and thus increased 
the magnitude of its electrical effects. In the original form 
of the experiment, a metal rod dipping into water in a glass 
jar was charged up with electricity from a frictional elec- 
trical machine ; the experimenter, holding the jar with 
one hand, touched the rod with the other, a spark passed 
to it and he felt a shock. This, if the jar had not been 
charged up strongly, was only momentary, but with 
stronger shocks it might take some time before he recovered 
complete control of his limbs, and very strong shocks were 
fatal. The “ electric shock ” aroused popular interest in 
physics to an extent that was not reached even by the dis- 
covery of Rontgen rays. Showmen travelled all over the 
cotmtry with their Leyden jars and electrical machines, 
giving people shocks for a small fee. At a fete attended 


by the King of France, one of the entertainments provided 
for the guests was to watch a file of soldiers, who had 
formed a chain by holding hands, leap convulsively and 
simultaneously in the air when the electricity from the jar 
went through them. Some people did not like these 
shocks. One Professor, after he had received one, said he 
would not have another even if he were given the kingdom 
of France. For this he is rebuked by Priestley in his 
History of Electricity. “ Far different were the sentiments 
of the magnanimous Mr Boze, who with a philosophic 
heroism worthy of the renowned Empedocles, said that 
he wished he might die by the electric shock, and that 
his death might provide an article for the Memoirs of the 
French Academy of Science.’* 

An accoxmt of various experiments made with the Ley- 
den jar, and one of the jars, was sent in 1746 as a present 
to the Library Company — a club of young men which had 
been founded by Franklin soon after his arrival in Phila- 
delphia — by Mr CoUinson, a friend of Franklin, who Kved 
in London and was interested in science. Franklin, aided 
by a few friends, at once began to make experiments and, 
in 1747, wrote a long letter to CoUinson, giving an account 
of his experiment, and the conclusions as to the nature of 
electricity to which he had been led. This was foUowed 
by other letters in 1748 and in 1749. In 1751 these letters 
were published in London without Franklin’s cognizance 
by CoUinson. They contain a very clear statement of his 
views of the nature of electricity. Electricity is regarded 
as a fluid whose particles repel each other. Matter when 
not electrified contains a definite quantity of this fluid ; 
if it contains more than this quantity it is electrified nega- 
tively if the fluid is regarded as constituting negative 
electricity, positively if it constitutes positive, while if it 


contains less than this quantity it is positively electrified in 
the first case, negatively in the second. The electrification 
of a body is due to the passage of this fluid into or out of 
it. Two bodies which have each more, or which have each 
less, than the normal amount of the fluid repel each other, 
while two bodies, one of which has less and the other more 
than the normal amount, attract each other. A similar 
view of the nature of electricity had been put forward a 
few months before Franklin’s letter by Watson, a Fellow 
of the Royal Society of London, and pubHshed in the 
Transactions of that Society. It was, however, Frankhn s 
letters, followed shortly afterwards by his remarkable 
experiments on Ughtning, which made his theory almost 
universally accepted. This was due to the clearness of his 
exposition, and to his showing that it gave a simple explana- 
tion of the many phenomena known to be associated with 
the Leyden jar, and led to the discovery of many new ones. 
This work, which together with his experiment on light- 
ning estabhshed his position as a physicist of the very first 
rank, must have been done in little over two years. He 
does not seem to have paid any attention to electriaty 
before 1745, and his first letter in 1747 contains the gist 
of the theory. He says himself that he never was engaged 
in any study that so totally engrossed his attention. H^ 
must have had quite remarkable insight and instinct m 
electrical matters. 

The service which the one fluid theory has rendered 
to the science of electricity, by suggesting and co-ordinat- 
ing researches, can hardly be overestimated. It is still 
used by many of us when working in the laboratory, h 
we move a piece of brass and want to know whether that 
will increase or decrease the effect we are observing, we do 
not fly to the higher mathematics, but use the simple con- 

benjamin franexin 

ception of the electric fluid which would tell us as much as 
we wanted to know in a few seconds. Modem researches 
have led to the view that electricity is carried from one 
body to another by electrons, particles whose mass is 
exceedingly small compared with that of the lightest 
atom ; that all these electrons are of the same mass and 
each carries the same charge of negative electricity. A 
collection of electrons would resemble in many respects 
Frankhn’s electric fluid, the idea of which was conceived 
in the infancy of the science of electricity. 

In 1752, Franklin made in Philadelphia the celebrated 
experiment of getting sparks and shocks by flying a kite 
carrying a pointed rod during a thunderstorm. It was 
characteristic of him that he should at once apply this dis- 
covery to useful purposes by inventing hghtning conduc- 
tors, long pointed rods reaching beyond the highest point 
of a budding and in metallic communication with the 
ground. The paper describing these experiments was sent 
in to the Royal Society, but was not thought worthy of 
publication in its Transactions, The Society made amends 
for this in 1771 by awarding him the Copley Medal, the 
highest honour in their power to bestow, electing him to 
the Fellowship of the Society, and reheving him from the 
payment of either the entrance fee or the annual subscrip- 
tion. In one of his visits to London in 1772, the Society 
appointed him a member of a Committee to report on the 
best way of protecting buildings from Hghtning. Caven- 
dish was a member of the same Committee, which 
reported in favour of sharply pointed conductors. One 
member, Benjamin Wilson, dissented because sharp points 
attracted the discharge and that, as we were ignorant of 
how strong it would be, it was better to keep out of its 
way than trust to getting rid of it safely when we had 



caught it. He was in favour of blunt ends. The battle 
between the sharps and the flats was complicated by poHti- 
cal considerations after the war with America began. 
Since the pointed ends had been invented by a rebel, 
George III ordered these to be removed from the hghtnmg 
conductors at Kew Palace and replaced by flat ones. He 
tried to make the President of the Royal Society, Sir John 
Pringle, support this change. The President rephed that 
the laws of Nature were not changeable at royal pleasure. 
It was then intimated to him by the King’s authority that a 
President of the Royal Society who held such views ought 
to resign, which he did.^ 

We know now that the action of lightning conductors 
depends upon properties of the electric current which w'ere 
not known in Franklin’s time. The passage of an instan- 
taneous outburst of electricity like a flash of lightning 
along a long metallic rod may, unlike the flow of a steady 
electric current, depend on other things besides the electri- 
cal conductivity of the rod, which was the only thing taken 
into account in designing lightning conductors until Sir 
OHver Lodge called attention to other important considera- 
tions in his lectures before the Royal Society of Arts in 1888, 
and if these are neglected the lightning conductor may be a 
danger instead of a safeguard. When the electrical cur- 
rents are rapidly changing, the effect of ordinary metaUic 
conduction becomes insigniflcant. The important factor 
is the self-induction of the circuit : this depends upon the 
length of the circuit, the longer the circuit the greater the 
self-induction. Thus a long circuit will offer a great 
resistance to the passage of the current, however great its 
metallic conductivity may be when the current is rapidly 
changing its direction. This means that the passage of such 
* A. H. Smytb, Life and Writings of Benjamin Franklin, vol. i. p. 107. 



currents produces large electric forces, which may cause 
electric sparks to fly off from the conductor, and these might 
produce serious damage. In his visits to England before 
the American War, Franklin must have frequently met 
Cavendish : they served on Committees together, and 
Franklin dined very frequently with the Royal Society 
Club, and Cavendish practically never missed a dinner. 
Cavendish too was at this time working on his paper, 
“ An Attempt to explain some of the Principal Phenomena 
of Electricity by means of an Elastic Fluid This fluid 
is practically the same as Franklin’s, whose paper, though 
it had been pubhshed more than twenty years before, is 
not mentioned by Cavendish. It is difficult to conceive 
two men more unlike. Cavendish’s interest was wholly 
concentrated on science ; he took no interest whatever 
in pohtical or social questions. Franklin, on the other 
hand, was interested in almost everything. Only a 
small fraction of his time was taken up with science : 
he played an important part in statesmanship, in pohtics, 
in municipal, social and even mflitary affairs ; he was fond 
of society and had multitudes of friends. Cavendish went 
out of his way to avoid meeting people and was a miso- 
gynist, which Franklin certainly was not. They differed 
as much iu' their scientific work. Cavendish’s paper on 
the electric fluid is mainly mathematical. He sets out his 
results in a series of Propositions, Lemmas and Corollaries : 
his object is to get results which can be tested by accurate 
measurements rather than to discover new phenomena. 
Franklin, on the other hand, never uses a mathematical 
symbol, but tests his theory by seeing if it will lead him 
to new discoveries. 

When dissensions arose between the mother country 
and its American colonies, Franklin was sent twice on 



missions to England to represent the view of the American 
settlers. He tried with all his might to get a peaceful solu- 
tion of the dispute : his efforts to do this failed, and he then 
threw his energies into helping America to get by war what 
she could not get without it, and in this he succeeded. 
During his stay in England he got acquainted with many 
of the most eminent men in this country. He was very 
popular with them ; was a guest of the Royal Society 
Club much more frequently than anyone else — in some 
years he dined as often as nineteen times with the Club. 
Those who came across him were much impressed by his 
ability. After he had appeared before a Committee of the 
House of Commons to represent the views of Pennsyl- 
vania on the Stamp Act, Burke said it was like a school- 
master being examined by a parcel of schoolboys. During 
the war he represented America for some years at Paris, 
and repeated the successes he had met with in London. 
He became, it was said, the best-known man in France. 
He had an immense correspondence, much of which has 
been preserved : it includes not only letters from dis- 
tinguished men of science and from prominent statesmen, 
but some from charming ladies beginning “ tres cher 

The French Academy lost no opportunity of showing 
how highly they esteemed him. Not only was he made 
one of its members, but his presence at their meetings was 
regarded almost as a royal favour. Whilst he was in 
Paris an Austrian physician, Mesmer, was arousing great 
excitement and making large sums of money by seances 
where those present were thrown into very abnormal 
mental conditions, and some were cured of diseases. Mes- 
mer ascribed these results to animal magnetism ; he sup- 
posed that his fingers emitted a magnetic effluvium which 


was a cure for many diseases. The King appointed a Com- 
mittee to report on this matter. On this Committee were 
several of the most eminent physicians and a number of 
scientific men, including Franklin and Lavoisier. Frank- 
Hn drew up the report, which, while admitting that some 
of the phenomena were genuine, rejected altogether the 
existence of animal magnetism and ascribed the effects to 
physiological causes. It is clear that they were examples 
of what would now be called hypnotism, and that Mesmer 
was a man who possessed the power of hypnotising people 
to a remarkable degree. He realised that there was money 
to be made out of it, and employed some of the methods 
of the charlatan to make as much as possible. His cures 
may have been quite genuine, for hypnotism was employed 
in medical practice to an appreciable extent in France 
towards the end of the last century. 

Physics, however, was only one of many branches of 
science in which Franklin did good work i he wrote on 
medicine, geology, aeronautics, agriculture, meteorology, 
pohtical economy, chemistry, hygiene. He always had a 
keen eye for the practical appHcation of any of his ideas. 
“ What is the use of it ? ” was the first thing he thought 
about. He upbraided himself if he indulged in “ wild 
flights of fancy , though he confesses to enjoy forming 
hypotheses, as they indulge his natural indolence : his most 
important scientific work, by the by, was the formation of 
a hypothesis. When he was working with the Leyden 
jar he apphed the spark to electrocution, and was able to 
kill a turkey weighing ten poimds. He made a multitude 
of inventions of very varied kinds, of which a new kind of 
clock, bifocal spectacles, and the Pennsylvania fireplace for 
preventing heat being lost by going up the chimney, are 
but a few. He does not appear to have sought to make 
257 s 


money out of them, for he says that the fate of a success- 
ful inventor is to be exposed to “ envy, robbery and 

Philadelphia owes to Franklin some of its most im- 
portant institutions . Soon after his first arrival there, when 
a boy of seventeen, he started a kind of Mutual Improve- 
ment Society wuth a few friends. This developed into the 
American Philosophical Society, the oldest scientific society 
in America, and also into the Union Library of Philadel- 
phia, one of the oldest and most interesting libraries in the 
country. The University of Philadelphia grew out of a 
College he had started, and the largest hospital in Phil- 
adelphia owes its inception to him. 

I gave five lectures at the Franklin Institute on “ The 
Electron in Chemistry ” : these were subsequently pub- 
Hshed under this title for the Franklin Institute, by the 
J. B. Lippincott Company. I give in the preface of this 
book my reasons for choosing this subject : “It has been 
customary to divide the study of the properties of matter 
into two sciences, physics and chemistry. In the past the 
distinction was a real one, owing to our ignorance of the 
structure of the atom and the molecule. The region in- 
side the atom or molecule was an unknown territory in 
the older physics, which had no explanation to offer as to 
why the properties of an atom of one element differed 
ftom those of another. As Chemistry is concerned mainly 
with these differences there was a very real division between 
the two sciences. In the course of the last quarter of a 
century, however, the physicists have penetrated into this 
territory and have arrived at a conception of the atom 
which indicates the ways in which an atom of one element 
may differ from that of another.” The electron is the 
dominating factor in this question, so that it is important 


to interpret chemical questions in terms of the electrons 
and their arrangement. This is what I attempted to do in 
the lectures. 

The lectures were very weU attended and in the 
audience were some of my old pupils, and many physicists 
whose work was quite famihar to me, though I had not 
till then made their acquaintance. 

I had a very busy but very dehghtful time duriug my 
stay in Philadelphia. I lectured at the Franklin Institute 
every afternoon and gave addresses at two universities, 
Haverford and Swarthmore, which were not far from 
Philadelphia. I had the honour of receiving an Honorary 
degree from the University of Pennsylvania, and two 
medals, the Scott and the Franklin, from the Franklin 
histitute. Dinners were given in my honour on three 
evenings, and at the farewell one my old friend Doctor 
Ames, of Johns Hopkins University, gave a much too 
flattering account of the work I had done. After my last 
lecture on the Friday, I joined my daughter at New York, 
and on Saturday sailed for England in the Homeric. We 
had bad weather aU the way home, but neither my daughter 
nor myself suffered any inconvenience from it. 

The Franklin Institute was founded in 1826. At the 
beginning its activities were confined to applied science, 
but it soon extended its scope and dealt with physics and 
chemistry generally and not merely with their applications. 
It has since its commencement pubhshed a monthly journal 
in which many valuable papers have appeared, and a 
very useful feature is that some of these are reports on 
the recent developments in some special branch of physics 
and chemistry. The Institute had just before my visit re- 
ceived a very handsome bequest, the Bartol Fund, which 
is to be devoted to research. They have established a 


Research Laboratory under the direction of Professor 
Swan, in which much interesting and valuable work has 
been done. 

While I was in Philadelphia I took the opportunity of 
visiting the famous Women’s University of Bryn Mawr, 
This is a residential university for both post-graduate and 
undergraduate women students. There are obvious advan- 
tages in having universities for women alone. They can 
choose the system which is best suited for women, while 
m co-educational universities the system has to have regard 
to the needs of the men as well as the women, and a 

compromise is adopted which is not the best possible either 
for the women or the men. I was very favourably im- 
pressed by what I saw of Bryn Mawr, and wish that we had 
one of the same type in England. The university has large 
buildings and attractive grounds. The students gave one 
the impression that they were thoroughly enjoying their 
College hfe, and did not confine their interests to the 
classroom. My visit to Bryn Mawr, which was, however, 
only a short one, left on me the impression that, though 
there are no male students at Bryn Mawr, the spirit of the 
undergraduate life was much more like that of the male 
undergraduates at Cambridge than was that of the women 
at the few co-educational Colleges I visited. 

Bryn Mawr was fotmded in 1880 and opened in 1885 ; 
at first nearly all the Professors were men, as in those early 
days of women’s education there were no women qualified 
for these posts. Now, however (1936), there are as many 
women as men holding Professorships. The success of 
Bryn Mawr is mainly due to the late Miss Carey Thomas, 
who was a very capable woman with a very pronounced 
personahty. She used the mailed fist rather than the 
and dominqe^d over the staff and the 


governors. It used to be said that Bryn Mawr had turned 
out more distinguished Professors than any other university 
in America, and this was pretty nearly true if you take 
“ turned out ” as meaning got rid of. Woodrow Wilson 
himself was one of her victims. She did not, however, 
always get the best of it. It is said that at a meeting of the 
Governors, when she was bringing a new scheme before 
them, one of them ventured at one stage to offer some 
criticism. Miss Thomas said, “ The point you raise, 
Mr Brown, is merely a side issue, we must keep to the 
main question At a later stage Mr Brown again 
raised some objection. “ Did not I tell you before, Mr 
Brown, that this is only a side issue.” “ Well, if you come 
to that, Miss Thomas, woman herself is only a side issue.” 

Miss Thomas may have been ruthless and domineering, 
but her thirty-five years’ untiring work was the main cause 
of the success of Bryn Mawi 


Harvard is more closely connected with Cambridge 
University than any other^. American university, since it 
was foimded by a Cambridge man. 

Some of those who came from England to America in 
the Mayflower and had originally settled in Boston, after a 
short time made a new settlement at a place a few miles 
away, which at first they called New Town, and in 1636 
they started a school or college, and changed the name of 
the place from New Town to Cambridge. In 1638 the 
Rev. Edward Harvard, M.A., Emmanuel College, Cam- 
bridge, one of the settlers, bequeathed to the College his 
hbrary and and in con^quence it was called Harvard 


College. It was attended at first by the children of the 
Indians in the neighbourhood, as well as by those of the 
settlers. From this humble origin, the College has in three 
himdred years grown from being not only the oldest, but 
also in some respects the most influential, in the United 
States. It has many more undergraduates than either Yale 
or Princeton, the other universities of its type. It has 170 
full Professorships (more than twice the number of those at 
Cambridge, England), covering almost every branch of 
hterature and science. It has, by general acknowledgment, 
the finest law school in the world. It has fine scientific 
laboratories ; it has one astronomical observatory in New 
England and another in South America, where the climate 
is better for observation ; it has a magnificent Hbrary, and 
its endowments have increased more than ten-thousand- 
fold. To come to fighter matters : it is the seat of a social 
club, the PorceUian, which I am told is about the oldest 
social club in America. The totem of the club is the pig, 
and its rooms are fuU of pigs of all sizes and materials : 
gold, silver, copper, ivory, ebony, glass, and many others. 

I am glad to say that there are many links between 
Harvard and Trinity College. Two of the Professors of 
Harvard are Trinity men — ^Professor A. N. Whitehead, 
F.R.S., a Fellow of Trinity College and formerly a Lecturer 
in Mathematics, and Professor Nock ; and if there are 
Trinity men at Harvard, there are also Harvard men at 
Trinity. Mr Lapsley came from Harvard to be a Fellow 
and a Lecturer in History in 1904. He is still, I am glad 
to say, at Trinity, and held for the appointed time the 
very responsible office of Tutor. Again, Harvard has a 
scholarship, the Fiske Scholarship, the holder of which has 
to become an undergraduate at Trinity, and we often have 
other Harvard men among our undergraduates. 



The vitality of the links with the past in this part of 
America is very attractive. You still &d people bearing 
the names of those prominent in American history centuries 
ago : these are naturally proud of their ancestry. 

I speak of a town in New England, 

The land of the mist and the cod. 

Where the LoweUs speak but to the Cabots 
And the Cabots speak only to God. 

But you can do more than find the old names ; here 
and there are still some, though very few, old houses in 
spacious grounds which have withstood the waves of city 
extension surging around them, and stand up as a memorid 
of times and customs which have long passed away. In 
such a house Uved my old friend and pupil, Theodore 
Lyman, for long Professor of Physics at Harvard, whose 
experiments on the spectroscopy of ultra-violet have led 
to results of fundamental importance, and who, besides 
being a distinguished physicist, is well known as a hunter 
of big game, and has devoted many vacations to that 
pursuit. When in 1932, largely through his exertions, 
the very fine new physical laboratory at Harvard had been 
completed, he retired from lecturing and became Emeritus 
Professor. He still, though his mother is now dead, hves 
with old-time servants in the house which he has hved in 
since he was a boy. He is a nephew of Alexander Agassiz, 
the distinguished naturahst, who was also intimately con- 
nected with the Calumet and Hecla copper mines. This 
connection was eagerly seized upon by the advocates of 
teaching more science in schools, who said that no doubt 
Agassiz from his knowledge of geology had been able to 
see that copper was likely to be found near the site of these 
mines, though no one before had suspected it, and that b^ 
buying up land in the district he had made a large fortune 


which he owed to his knowledge of geology. His sister, 
Mrs Lyman, when I was staying with her, once told me 
after dinner, how her brother really got connected with 
these mines, and the true story is not nearly so useful for 
pointing a moral as the old. She said : “ When Alexander 
was a freshman at Harvard, he got acquainted with a happy- 
go-lucky kind of undergraduate who was always trying to 
borrow money from his friends, and he borrowed some 
from Alexander. After a time the borrower’s affairs came 
to a crisis. A meeting was called, and the assets divided 
among the creditors : as Alexander was the youngest of 
these, his turn came last, and the only thing left was a piece 
of land in a place he had never even heard of, much less 
seen. He protested vigorously against having to take it, 
but it was that or nothing, and nobody would buy it from 
him. This was the land on which the Calumet and Hecla 
mines were afterwards discovered.” 

President Ehot introduced during his term of office a 
very interesting scheme called the “ Elective Scheme ”, in 
which the candidates for degrees could, with certain 
restrictions, choose for themselves out of a long and 
varied Hst of subjects those on which they would be 
examined for their degree. This scheme is in accordance 
with the principle, which I believe is a sound one, that 
a student gets a better training by studying a subject which 
interests him than one which does not. The experiment 
was not very successful, and now the “elective principle” 
at Harvard has been modified and restricted. It had been 
found that the subjects which were chosen by the greatest 
number of students were the “ soft options ”, the subjects 
where the number of marks required to qualify for a degree 
could be obtained with the minimum amount of work. 

The fact is that a large number of students have, to 


begin with, no special interest in any branch of learning. 
This interest has to be aroused by the teacher, and to do it 
he must be a good lecturer, clear, forcible and interesting. 
Above all, interesting : such teachers are not easily found. 
Moreover, if the practice in American universities is the 
same as it is in Cambridge University, surprisingly Httle 
attention is paid in elections to Professorships to the powers 
of the candidates as lecturers. The evidence as to the 
soundness and extent of their knowledge, and of the value 
of their own contributions to knowledge, is very carefully 
considered, but that about their power of presenting a 
subject in a clear and attractive way does not receive 
nearly so much attention. I think myself that this is to be 
regretted. On my view the most important function of 
lectures is to arouse the interest of the students rather than 
to impart information ; to make them so interested that 
they wiU get the information for themselves if they are 
told where to find it. I think the lecturer should give the 
students something that they cannot easily get from books, 
as, for example, when his lecture is accompanied by ex- 
periments, or is on some discovery or idea of his owm : this 
perhaps arouses their interest more than anything else. At 
present I think many of our students are over-lectured. 
They spend so much time in going to lectures that they 
have no time to think about the subject for themselves. 

t All American universities have received great gifts from 
their old members : the Harvard graduates are so en- 
grained with this idea that it is said that a wealthy Harvard 
man would feel that he had tarnished his reputation if he 
omitted to leave something to Harvard in his will. They 
lost what would have been perhaps the greatest benefaction 
that a university ever received, when a man and his wife, 
who showed no signs of affluence, called on President 


Eliot, and said that they had just lost their son and wished 
as a memorial to him to do something to help other young 
men to get a good education, and would he grateful if 
President Eliot would tell them how to do so. The 
President said that he was afraid that it was impossible to 
do anything in that way except at a great expense. This 
suggestion of impecuniosity nettled the lady, and she said, 
“Well, President Eliot, what has this university cost, 
buildings, professors and aU ? ” The President mentioned 
a great many milUon dollars, and the lady said, “ Come 
away, Leland, I think we can do better than that”. 
They went away and founded the Leland Stanford 
University, with an endowment of 34 million dollars. 



Some Trinity Men 

W. H. Thompson 

had been Master of Trinity since 1866, died in 
1886. Before his election to the Mastership he 
had been a lecturer and tutor of the College, Regius Pro- 
fessor of Greek and Canon of Ely. His lectures as College 
Lecturer, and also as Regius Professor, on Ancient Philo- 
sophy, were exceptionally brilliant and attracted very large 
classes. His pubHshed work, however, was small, and in this 
respect, and indeed in almost every other, he was a great 
contrast to his predecessor William Whewell, who was 
a very voluminous writer, very energetic and somewhat 
overbearing. Whewell was, however, instrumental in in- 
troducing many reforms which have proved very bene- 
ficial. He was also a great benefactor to the College and 
erected at his own cost Whewell’s Court, the part of the 
College to the east of Trinity Street. Though he made 
no discoveries himself, by writing The History of the Induc- 
tive Sciences, and The Philosophy of the Inductive Sciences, he 
rendered good service to science. Faraday consulted him 
about the nomenclature he should use in describing his 
discoveries, and it is to him that we owe the terms electrode, 
cathode and anode. He was much more successful as an 
author than as College Tutor ; he seems to have known 
very httle about his pupils. In his time the Scholars of 


the College were elected by the three tutors. One of 
these, it was said, always voted for his own pupils ; 
another was so conscientious that he always voted against 
them for fear of being unduly biassed; while of Whewell 
it was said that he was quite impartial, for he did not know 
who were his pupils. He was extremely punctilious about 
the behaviour of xmdergraduates when in his presence. 
If an undergraduate sat down at one of his evening parties, 
a servant came up and said, Undergraduates are not 
allowed to sit in the presence of the Master I can 
vouch for the truth of this, because I have met a man who 
was present when this was said to a friend of his who had 
gone with him to a party at the Lodge. This made him 
unpopular with the undergraduates, but on the death of 
his second wife. Lady Affleck, they showed so much sym- 
pathy that he was greatly touched, and his relations with 
them became much more cordial. He was killed by a fall 
when riding : he was a heavy man and the fall proved 
fatal. I think he must have been in the habit of falling, 
for one day I noticed in my tailor s shop a medallion of 
Dr. Whewell. I asked whether he had been a customer 
of theirs. “ Oh yes, sir, he was the best customer we ever 
had.” I said I did not know he was a dressy man. 

Well, sir, he was not what you might call a dressy gende- 
man, but he was one who took to riding late in life.” 

There can have been few, if any, periods in the history 
of the College when it had more undergraduates destined 
to attain outstanding distinction as men of letters than that 
between 1829, when Thompson came up as a Freshman, 
and 1832, when he took his degree. Among his con- 
temporaries were Alfred Tennyson, Arthur HaUam, W. M. 
Thackeray, Lushington, “ wearing all that weight of 
learning lighdy as a flower ”, FitzGerald, the translator of 


Omar, Monckton-Milnes (Lord Houghton), Spedding (the 
Baconian scholar), W. H. Brookfield,^ who became a very- 
popular preacher, and who had a great fund of good 
stories. Thompson, in a letter which has been published, 
says that on one occasion his hearers were in such con- 
vulsions with laughter that they could not sit in their chairs 
and had to take refuge on the floor. During his Master- 
ship the statutes of the College were twice revised and 
gready changed. New statutes were proposed in 1872 
and in 1882. The changes proposed by the College in 
1872 never came into force as they were disallowed by the 
Privy Council. The changes proposed in 1882 were in 
force until 1926, when they were replaced by statutes 
made by the Cambridge University Commissioners. The 
changes in the statutes involved weekly meetings of the 
whole body of Fellows during term time, over which he 
had to preside. The meetings about each of these changes 
lasted over a period of more than a year and a half, and 
some of them were very long ; one, with two short 
adjournments, went on from ii a.m. to 12 p.m. This 
entailed a very heavy strain on the chairman, especially 
as the Fellows were very much divided on the best course 
to pursue. Henry Jackson, who attended both sets of 

I I once had a very curious experience with which both Thackeray and 
Brookfield were concerned. Not long after I became a Fellow, at the 
end of a busy term, I went to Brighton for a few days to get freshened up. 
At dinner on the first evening I sat next a middle-aged lady I had never seen 
before, and had not the faintest idea who she was. After the usual common- 
places, she said, Now I want you to tell me who is your favourite heroine 
in fiction ”, One does not expose one’s deepest feelings to strangers, so, 
on the spur of the moment, I said Thackeray’s Amelia, and was going on 
to say mat I thought her a very well-behaved and good-natured girl. 
Fortunately before I could do this, she exclaimed, “ I’m so glad to hear 
you say so, because I’m the original Amelia. I’m Mrs Brookfield and both 
niy husband and I were great friends of Thackeray.” I sat next her at 
dinner during my short stay at Brighton, and she told me many interesting 
things about Thackeray and his domestic troubles. 



College meetings, said the passing of the statutes owed 
much to Thompson s initiative and resolution. 

I never saw Thompson until he was an old man, and 
he was one of the handsomest old men I ever saw : he 
had silvery-white hair, sharply cut features and a very 
dignified presence . There is a portrait of him by Herkomer 
in the Hall of Trinity College. It somewhat accentuates 
his severity and he looks rather bored. This, I think, was 
because he and the artist may not have had many interests 
in common. Herkomer was, however, very well satis- 
fied with his performance, for he told me that he thought 
two at least of his pictures would keep his memory green. 
One was this portrait, and the other the portrait of Mss 
Grant, a tall lady in white satin. The Master is seated in 
an armchair with his hands gripping the ends of the arms, 
and this was the cause of a curious incident. Some time 
after I became Master, I was showing a distinguished 
physician the pictures in the Hall, and when we came to 
this one he said, “ That man must have had a stroke I 
had been up at Trinit7 during ten years of Thompsons 
Mastership and never heard any rumour of such a thing, 
and said so. The doctor said he was sure he was right, for 
no one ever gripped a chair like that who had not had a 
stroke. On enquiry I found the doctor was right, but the 
matter had been very carefully hushed up. 

Though he had a sharp tongue he had a kind heart, 
and in spite of his glacial exterior he was very human. I 
did not find this out until some time after taking my 
degree. When I was an tmdergraduate I had often been 
to breakfast parties, which he and Mrs Thompson gave on 
Saturday mornings in term time, and had thought him so 
formidable that I tried to get to the other end of the table 
near Mrs Thompson, who was a very kind-hearted and 


friendly lady. She must have found it hard work to 
make these parties successful. Most of the undergraduates 
were very shy ; many of them she had never seen or 
heard of before, and did not know what they were 
interested in, so she had to turn the conversation on to very 
neutral topics. There was a tale current in my time, that 
some years before, when among the scholars there was 
one named Lamb, who became Sir Horace Lamb and a 
very famous mathematician, and another named Butcher, 
who became a very distinguished classic and M.P. for the 
University, she invited both to breakfast and sat between 
them. In the course of breakfast she said she supposed she 
ought to feel very nervous, because it must be dangerous 
to be between the butcher and the lamb. The story went 
on to say that as soon as she had said this the Master broke 
in with, “ Personal remarks are in the worst possible 
taste I once asked Sir Horace Lamb, who ought to 
have known, if there were any truth in this, and he said, 
“ Not a word. The tale was concocted at the time by 
one of the College wits.’' I thmk even the shyest of us 
were very glad to go to these breakfasts, and looked on an 
invitation as a mark of distinction. 

I discovered how human the Master was when, one 
dreary afternoon in November, after I had taken my 
degree, I had to go to him to get his signature to a certificate 
of residence. After he had signed it he asked me to stay, 
and began telling me stories, some of them very frank, 
about past and present Fellows of the College, and went 
on until the bell for dinner in Hall began to ring. He 
evidently enjoyed chatting in this way, for he asked me 
to come again any afternoon when I had an hour or two 
to spare. ^One of the stories he told me was about 
Thackeray, who was in his year. The undergraduates at 


that time were examined at the end of the May Term, and 
the places in the examination room were arranged alpha- 
betically. This brought Thackeray and Thompson next 
each other. In the morning the paper was on Elementary 
Algebra, and Thompson, for a classical man, was a fair 
mathematician. At any rate, he was good enough to find 
something to do on this paper, and wrote sheet after sheet. 
Thackeray whispered to him, “ It would be a great help 
to me if you would turn your papers round so that I 
could read them ’ ’ , and Thompson did so . (No emolument 
of any kind depended on the result of this examination.) 
The paper in the afternoon was Greek verse. Thackeray, 
who fancied himself as a classic, went off at a great pace 
and finished well before the allotted time. As he was 
going out he handed a copy of his verses to Thompson 
and said, “ You were very kind to me about the Algebra 
paper this morning ; if these verses are of any use to you 
they are quite at your service The Master, when he 
told me the story, said, “ I had the curiosity to read them, 
and there wasnT a line without a gross blunder He 
was remarkably imperturbable. I remember a sermon of 
his in Chapel, when for once he was ending with what 
was, for him, quite a fervid exhortation. Just before the 
end, he lost his place and it took him quite an appreciable 
time to find it. When he did, he started in exacdy the 
same high tone as he had left off. The effect of this 
syncopated earnestness was quite startling. 

To the outside world he was perhaps best known as 
the sayer of witty things. When Seeley succeeded Kings- 
ley in the Professorship of Modem History, Thompson, 
when coming away from his inaugural lecture, said, “ I 
never thought we should have missed Kingsley so much ”. 
He said when he was Canon of Ely, “ Ely is a very damp 


place ; even my sermons won’t keep dry there He 
could even descend to puns. When the valet Courvoisier 
was hanged for murdering his master, he said it was the 
fulfilment of the prophecy, “Every valley shall be exalted”. 

The most widely known of his sayings, “We are none 
of us infallible, not even the youngest ”, was made at a 
meeting of the Fellows for the discussion of proposed 
changes in the statutes of the College. Some have thought 
that it was levelled at a particular Fellow, and there have 
been several claimants for this distinction. I was not then 
a Fellow and did not hear it, but it was much talked about 
in the College at the time, and I think most people thought 
that it was impersonal. It was said at the end of a long 
discussion in which most of the talking had been done 
by the younger Fellows, and the Master may have thought 
that his remark embodied a principle which was pertinent 
to the occasion. 

Dr. Butler 

Dr. Thompson, whose health had been failing for some 
time, died in 1886. The Master of Trinity is appointed 
by the Crown, whereas with one exception the Masters 
of other Cambridge Colleges are appointed by the Fellows. 
Proposals have from time to time been made in Trinity 
that the College should endeavour to have the statutes 
altered so that the election to the Mastership should be 
made by the Fellows as at the other Colleges. These 
have not met with much support. Though it may not 
be democratic, there are advantages in the present method. 
When the election is in the hands of the Fellows, and 
opinion is nearly equally divided, there may be a keen 
fight. It is possible, indeed it has happened both at 

273 T 


Oxford and Cambridge in a few cases, that this may leave 
behind embers of bitterness which may destroy the har- 
mony of the College. This, in 1886, was the first vacancy 
at Trinity since the new statutes came into force, which per- 
mitted the election of a layman. At this time there were 
only two laymen who were heads of Colleges ; now there 
are only two clerical heads. There was naturally a good 
deal of speculation in the College about who would he 
the new Master. I think that perhaps the majority of 
the resident Fellows hoped it would be a layman, and the 
names of Lord Rayleigh and Henry Sidgwick were 

It was, however, offered to and accepted by Henry 
Montagu Butler, the Dean of Gloucester, who had had an 
exceptionally brilliant career. When he was at Cam- 
bridge he was regarded as the most brilliant undergraduate 
in residence. He was Senior Classic, had won a Univer- 
sity Scholarship for Classics, had been one of the 
“ Apostles and was elected to a Fellowship at his first 
try. In 1859, when he was only twenty-six, he was 
elected Head Master of Harrow in succession to his father, 
and filled this post with brilliant success for twenty-sbc 
years. He was made Dean of Gloucester by Mr Gladstone 
in 1885, and Master of Trinity by Lord Salisbury in 1886, 
and was admitted as Master on December 3, 1886. After 
dinner that evening his health was proposed by the Vice- 
Master, Coutts Trotter, an old Harrovian. The Master's 
reply made a very favourable impression. It showed 
warm affection for the College, paid tribute to the merits 
of the late Master and of Dr. Whewell, spoke very 
modestly about himself and said that the College must not 
look to him for originahty or research. Any gifts he had 
were of a lighter kind, but such as they were they were 


ail at the disposal of the College. The task the new 
Master had undertaken was no hght one. The University 
and the College were very different from what they were 
when he left Cambridge twenty-seven years before. The 
College under the statutes of 1882 was governed as far 
as its normal business was concerned by a Council con- 
sisting of 8 members elected by the Fellows, and 4 ex- 
officio members, with the Master as Chairman. He had a 
casting vote and on some occasions his vote counted for 
two, otherwise he had no powers beyond those of a chair- 
man of a Governing Body. Under the statutes in force 
when Dr. Butler left Cambridge, the Master had much 
greater powers and the Fellows less, for then membership 
of the Governing Body went by seniority and not by 

I am afraid that at first Dr. Butler did not find presiding 
at the meetings of the Council very pleasant. The mem- 
bers of a body which, hke the Coundl, meets very fre- 
quently, easily get into the habit, like the members of a 
large family, of saying what they thiuk without taking 
much trouble to put it into the most polite forms, and to 
one who came in from the outside they might be thought 
rude. This did not, however, affect their friendship. 
Those who had been squabbling at the Council Meeting 
would; at the lunch after the meeting, be the best of triends. 
To Dr. Buffer, however, who was the most courteous of 
men, these outbursts were very distressing. This, I think, 
was soon realised by other members of the Cotmcil, and 
they were careful to carry on their discussions in a way at 
which no one could take offence, a practice which has been 
the custom up to the present time. 

Another thing which caused him some uneasiness was 
the reserve, which is often supposed to be characteristic of 



Fellows of Trinity, in the expression of their feelings, 
especially those of approval. It may be that some things 
go without saying, but it is also true that many of these 
are the better for being said. If a friend has had a success 
it is better to send him your congratulations than to leave 
him to take them as read. Dr. Butler was most scrupulous 
about this : anyone he knew who received some distinc- 
tion was sure to have his pleasure enhanced by the receipt 
from him of a letter such as no one but he could have 
written, full of charm, grace and kindliness. He was as 
unrivalled as a letter-writer as he was as a speaker. The 
number of letters of this kind he wrote must have been 
very large, for any Trinity undergraduate who won any 
distinction, either in the College or in the University, was 
sure to have the pleasure of receiving one. It seemed to 
him to be so natural to write to his friends to express his 
appreciation of what they had done that, if he did not 
receive any such expression, he concluded that what he 
had done was not appreciated. The Fellows of Trinity 
were very reticent about expressing their feelings, and the 
Master felt as if he were surrounded by chilling indifference, 
and indeed a meeting of the whole body of Fellows is 
about the most difficult audience to address I know. It is 
as difficult and depressing as broadcasting a speech or 
speaking in the dark. I think, however, the Master 
realised, as the years went on, that he had gained not only 
the admiration and respect of the Fellows but also their 

Dr. Buder’s Mastership was characterised by almost 
boundless hospitahty and generosity. In a letter to Dr. 
Westcott dated May 9, 1887, he writes: “ When I accepted 
my very peculiar post it seemed to me clear that hospitality 
on a large scale, righdy understood, was one of my plain 


duties. It seemed to me that the Lodge as time went on 
ought to bring together the leading members of the 
University, the Fellows and Scholars, friends from a 
distance, leaders in good causes, whether here or away. 
... I determined that parties at the Lodge should be 
very numerous and very various. ... As some little test 
of variety I may just say to-day, as on Saturday, I have 
large parties to meet Sir George Trevelyan, our Honorary 
Fellow ; on Friday I have a meeting of perhaps eighty or 
one hundred to work for the Toynbee Hall Settlement ; 
on the 14th the Ro undells, Godley, Sir M. Ridley and 
Charles Dalrymple come. On the 17th we have a large 
party with which I think you will sympathise. I hope it 
will begin a yearly institution. I am inviting the newly 
elected scholars to meet the Vice-Master, the Tutors and 
some of the older Fellows. . . . On the 21st the George 
Hamiltons, Fowell Buxtons and others come. . . . Last 
Saturday we had forty of the Colonial Delegates.*’ In 
addition to his own hospitality he increased that of the 
College, for it was largely due to him that the College 
instituted in 1889 the “ Old Boys ” dinner, to which 
members of the College who had kept their names on the 
College books were invited in groups to dine and sleep at 
the College. Efforts are made that as far as possible t 5 iey 
shall be given the rooms they had when they Hved in 
College. These dinners have proved a very great success ; 
the guests welcome the opportunity of meeting old friends, 
and of keeping in touch with the changes and progress of 
the College. At these dinners Dr. Butler’s speech was one 
of the greatest attractions, for on occasions like these he 
was unrivalled as a speaker. He always said the right 
thing in the right way. He had a marvellous memory 
and had read very widely. Whatever might be the day 


on which he had to make a speech, he would always 
remember some interesting event of which it was the 
anniversary. He could enliven and drive home the point 
he wished to make by a happy quotation from some great 
statesman, orator or poet. The manner in which his 
speeches were delivered added greatly to their effect. He 
had a very agreeable voice and until near the end of his 
life it was easy to hear him. The dignity of his presence 
and manner were an important factor in the success of his 
speeches, and never more so than at the “ Old Boys 
dinner when, ‘‘ Erect in his scarlet robes at the centre of 
the High Table, the three great circles of silver plate gleam- 
ing on the panelled wall behind him, he seemed worthily to 
represent before the world the majesty of the College 
The Master preached several times a term in the 
College Chapel. His sermons had the felicity in phrasing 
and wealth of illustration of his speeches. Added to this 
there was an earnestness and reverence which made them 
very impressive. They were very simple and practical 
and seemed to me just the right kind for an audience of 
undergraduates. He made the sermons in Chapel much 
more attractive than they were before he became Master. 
Then, sometimes, we had sermons from a preacher who 
was so determined to be impartial that, when preaching on 
some article of Christian belief, he would spend so much 
time over the argtiments that might be advanced against 
it that he had very little time to give those in its favour. 
Another preacher was so obHvious of worldly affairs that, 
when Gilbert and Sullivan’s opera H.M.S, Pinafore was at 
the height of its popularity, he began a sermon by saying 
with great solemnity, ‘‘Never or hardly ever”. The 
undergraduates, to suppress their emotions, had hurriedly 
to bury their heads in their hands. The eloquence and 


charm of the Master’s speeches led to his being besieged 
with invitations to preach, to address meetings for the 
promotion of all kinds of objects, educational, philan- 
thropic and missionary. He was, too, a Governor of six 
public schools. This made his name and fame better 
known to the educated classes of this country than that 
of any other Master of Trinity. There had been Masters 
who had been as well or even better known to the class 
which haunts the Athenaeum Club, but none whose name 
was known to so many men of widely different activities. 
He was interested in all these, and while he sympathised 
warmly with the efforts of the College to promote learning 
and research, since only a small fraction of the under- 
graduates who passed through the College could aspire 
to write great books or make important discoveries, he 
felt that another and no less important function of the 
College was to tram the great majority of the under- 
graduates so that they should be well fitted to carry on the 
work of the coimtry, whether this was in pohtics, in the 
law courts, in the Church, as proconsuls or ambassadors, 
in the Civil Service, in teaching, m engineering or com- 
merce. When they obtained distinction in their respective 
spheres, he rejoiced as much as he did in the distinction 
obtained by those who were working at more academic 
subjects. He took a keen interest in games, as was natural 
for one who had been captain of the Harrow Eleven and 
was the father and grandfather of captains. His eldest 
son, E. M. Butler, played twice in the Oxford and Cam- 
bridge Cricket Match and twice represented Cambridge 
in the Racquets Match. His grandson, Mr Guy Buder, 
ran the quarter-mile three times for Cambridge in the 
Oxford and Cambridge sports and was never beaten : he 
was the best quarter-miler of his time. I never saw a more 


recollections and reflections 

magnificetit example of physical energy than the way he 
tore down the straight and forced himself in front in the 
last few yards. Though Dr. Butler approved and took an 
interest in games, he thought that at some schools and 
universities the hero-worship given to the athlete was 
excessive and mischievous. 

On July 2, 1913, his eightieth birthday, an address 
signed by all the Fellows and written by Professor Hous- 
man, was presented to him. It runs : . They remem- 

ber . . . above all, the years of genial and dignified 
maturity during which you have presided over Trinity 
College, your ardent zeal for its common welfare, your 
considerate kindness towards its individual members, 
young and old, and the union of charm and authority 
with which you have represented it within the University 
and before the world ; they recall the wisdom and tact 
with which you have fulfilled the duties of your office, 
and the prompt and graceful eloquence, issuing from rich 
stores of reading and memory, with which you have 
adorned it. 

Coutts Trotter 

Coutts Trotter, who died in 1887 3 -^ 3ge of fifty, 
had taken, I think, a larger share than anyone else in the 
great developments in the opportunities for study and 
research which took place between 1870 and the time of 
his death. He took honours, though not very high ones, 
in 1859, in both the Mathematical and Classical Triposes. 
After taking his degree, he was for two years a curate in 
Kidderminster : after his election to a Fellowship in 1862 
he went to study in Germany, and attended the lectures 
of Kdrchhoff and worked at physiology in Helmholtz’s 



laboratory. He was elected to a lectureship in Science in 
Trinity College in 1869, to a tutorship in 1871, and was 
Vice-Master at the time of his death. He was not, how- 
ever, particularly successful either as lecturer or tutor, and 
he did very Httle original research. His real work was 
the help and sympathy he gave to all schemes which 
seemed to him likely to promote the study of science either 
in the College or m the University. He had great influence 
in both ; he took a very prominent part in the affairs of 
the College, while m the University he was a Member 
of the Council of the Senate continuously from 1874 until 
his death, and also a member of every syndicate that was 
concerned in any way with science. I think he must 
have spent a large fraction of his time in attending the 
meetings of these bodies. He was a most useful man on 
a committee : he knew his own mind and could express 
his ideas clearly and was exceptionally skilful in drafting 
resolutions. He was invariably courteous, even when, as 
was sometimes the case, his proposals met with fierce 
opposition, which was not always very poUtely expressed. 
One who worked with him on many committees, said 
that it was always he who formed the first plan and 
drafted the final report. His services to science were not 
Hmited to his work on committees ; he took a great 
interest in the planning and erection of the many labora- 
tories which were built in his time. When the plans of 
the Cavendish Laboratory were under consideration, he 
went with Clerk Maxwell on visits to many physical 
laboratories, so that the new laboratory might be brought 
abreast of recent progress. Michael Foster has testified to 
the interest he took in the construction of the new Physio- 
logical Laboratory and the laboratories for Botany and 
Zoology, and the value of his suggestions. One very 


important service he rendered, both to Trinity College 
and to the University, was the part he took in bringing 
Michael Foster to Cambridge. The first step in this is 
generally beheved to have been taken by George Ehot 
and George Henry Lewes, who were friends of W. G. 
Clark, the well-known Shakespearian scholar, who was a 
Fellow of Trinity. They asked him if some post could 
not be found in Trinity for Foster. This suggestion was 
warmly supported by Trotter, with the result that the 
College estabhshed a new post, Praelector in Physiology. 
Foster came to Cambridge as Praelector in 1870 and re- 
mained in it until he was made Professor of Physiology 
in the University in 1883. The estabhshment of this 
Praelectorship enabled physiology to be studied in the 
University much sooner than it would have been if it 
had had to wait until the University was m a position 
to found a Professorship in this subject. Trinity College 
did the same thing for biochemistry by appointing 
Gowland Hopkins to a Praelectorship in this subject in 
1910, and for geodesy by appointing Sir Gerald Lenox- 
Conyngham to one in 1921. 

A very fundamental change in the method of election 
to Fellowships in Trinity College was to a very large 
extent due to the influence of Trotter. Until 1874 the 
election was determined solely by the performance of 
the candidates in a written examination, but in that year 
the College decided that candidates could gain credit not 
only by their performance in the examination, but also 
by the merits of a dissertation containing an account 
of original research carried out by them, which they were 
allowed to submit to the Electors. This has proved 
so successful that the paper work in special subjects has 
been abandoned, and the awards decided on the merits 


of the dissertations. The importance Coutts Trotter 
attached to research is perhaps even more strongly empha- 
sised by the regulations for the Coutts Trotter Studentship, 
for which he bequeathed to the College a legacy of about 
^7000, for a studentship for the promotion of original 
research in Natural Science, more especially physiology 
and experimental physics. The studentship is not to be 
awarded by examination, and in the election more regard 
is to be paid to the promise of power to carry on original 
work than to the amount of work already done.” Among 
former Coutts Trotter students are Lord Rutherford, Lord 
Rayleigh and Professor O. W. Richardson. 

In my opinion, research has great educational value 
and can be made a good test of a man’s mental power. I 
have often observed very striking mental development in 
students after they have spent a year or two on research : 
they gain independence of thought, maturity of judgment, 
increased critical power and self-rehance, in fact they are 
carried from mental adolescence to manhood. It is 
essential, however, that when using the dissertation as a 
test of mental power, other things should be taken into 
account besides the scientific importance of the results it 
contains. This may be due to his teacher having suggested 
to the candidate a problem which led to perhaps un- 
expectedly interesting results, and to having helped him 
out of his difficulties almost as soon as he got into them. 
In such a case the dissertation may not prove more than 
that the candidate is industrious and a careful experi- 
menter ; it does not prove that he is capable of making 
discoveries without guidance. I think when once the 
research has been started, the student should be encouraged 
to try to overcome his difficulties by his own efforts, and 
that the assistance given by the teacher should not be 



more than is necessary to keep him from being disheartened 
by failure, and to prevent the work getting on lines which 
cannot lead to success. 

Again, the candidates for Fellowships are allowed to 
send in dissertations on any subject they please, and the 
Electors to the Fellowship are faced with the difficulty of 
comparing the merits of dissertations on subjects as varied, 
say, as Stieljes Integrals, Byzantine Art, Radio-activity, the 
Pohtical Life of Sir Robert Peel, and the Flora of a Tropi- 
cal Forest. Again, the dissertations are reported upon 
by Referees, and to estimate the value of the report it is 
necessary to know something of the temperament of the 
Referee. Some Referees are prodigal in their use of super- 
latives, others very sparing. Reporting on the same paper, 
one may say, “ that this paper is the most important 
contribution to the subject made in the century ; the 
other that “ it is quite a creditable piece of work”. Those 
who know the Referees know that the difference in their 
reports is due to the difference in their way of expressing 
their views, and not to any real difference in the views 
themselves- If the predictions of all the Referees had been 
realised, then at the elections I have myself attended we 
should have added to the roll of our Fellows four Newtons 
and three Bentleys. On paper our method of electing 
Fellows seems hopeless, but, like many things in this 
country, methods which seem hopeless on paper, work 
fairly well in practice, and it has been so in this case. We 
have made mistakes, but they have been surprisingly few. 

Until the statutes of 1926 came into force, anyone 
elected to a Fellowship held it, and received its emoluments 
unconditionally, for six years. He was not even required 
to reside in College. If he wished to go to the Bar, the 
Fellowship would enable him to tide over the lean years 


before he had. built up a practice. Some who have held 
high legal offices have been enabled to do so by a Trinity 
Fellowship. Some, too, went into the Civil Service, some 
into politics. The system gave each Fellow an oppor- 
tunity of taking up the work in which he felt his strength 
to lie and in which he was most interested. It also brought 
the College into touch with the work of the nation, and 
helped the College to fulfil its duty to the nation by 
supplying for its service able men who without it might 
not have been available. Under the system which came 
into force in 1926 the tenure of the Fellowship is only four 
years, and for at least three of these the candidate, before 
he receives any emolument, must produce evidence that 
he has been engaged in research. This practically compels 
him to take up an academic career. He would be too old 
at the end of four years to enter any other profession, and 
if he did he would not receive any emolument from the 


A. G. Dew-Smith, who for many years lived in rooms 
in College and was a member of the High Table, was a 
prominent figure in our Society in the eighties. He was 
not a Fellow, nor did he hold any University appointment, 
so that by our statutes he had no legal claim to rooms in 
College : he was granted these because he rendered im- 
portant assistance to the School of Physiology by relieving 
Michael Foster, who was a great friend of his, of much 
financial and administrative business. He was of a type 
not often found in our Society, famihar with life in London 
and especially with Club life. Robert Louis Stevenson, 
who sometimes stayed in Trinity for the week-end on 



visits to Sidney Colvin, is supposed to have represented 
him in Attwater in The Ebh-Tide. To my mind he was 
more like Prince Florizel in The Dynamiters. He was a 
man of fine presence and distinguished manners, and, if 
he had kept the tobacconist shop in Rupert Street, he 
would have handed a packet of cigarettes over the counter 
with the air of a monarch presenting the insignia of a 
Knight of the Garter to one of his subjects. 

Dew-Smith, too, was one of the best photographers of 
his day, and photographed many distinguished people : 
his portrait of Professor Cayley was a great success. His 
most important work, however, was starting a workshop 
in Cambridge for making scientific instruments. It is of 
the first importance that a laboratory where research is 
carried on should have a workshop connected with it. 
Each new piece of research generally requires apparatus 
which cannot be bought ready-made from the instrument- 
makers, but has to be made to order. This leads to delay, 
checks the progress of the research and increases the 
expense. At first the Physiological Laboratory had no 
workshop and no funds to equip one, or pay the wages of 
a skilled mechanic. Dew-Smith, at his own charge, took 
a small house in St. Tibbs Row not far from the Laboratory, 
fitted it up as a workshop, and engaged a very skilful 
mechanic named Pye, while he himself devoted a good 
deal of his time to the business side of the workshop and 
its superintendence. Pye himself was a bit of a “charac- 
ter ” as well as a good workman ; he held very decided 
views about most things, including the merits of those for 
whom he was making apparatus. He expressed these 
views quite freely, to the great dehght and amusement of 
his master. 

The workshop was very successful. It began by 


making comparatively simple apparatus. The laboratory, 
however, soon required much more elaborate pieces. The 
construction of these required greater knowledge of science 
and of mechanical engineering than either Dew-Smith or 
Pye possessed. These were suppUed by Mr (later Sir) 
Horace Darwin. By his aid the magnitude and scope of 
the work increased until the workshop in Tibbs Row 
developed into the Cambridge Scientific Instrument Com- 
pany, which has done much to increase the advance of 
science by the accuracy of their workmanship, and their 
enterprise in producing new types of instruments as soon 
as the progress of science requires them. 

Joseph Prior 

Joseph Prior was a very prominent figure in the social 
hfe of the College for nearly sixty years and had, I think, 
been the tutor of more undergraduates than anyone in the 
history of the College. He was Tutor for sixteen years 
while the normal tenure is not more than ten. His was 
the longest tenure since the end of the eighteenth century, 
and though some tutors before that time had a longer one 
— for example, Thomas Jones was Tutor from 1787 to 1807 
— the number of imdergraduates in the College was then 
very much smaller than it is now. Prior had, I should 
think, about 750 pupds in his sixteen years and Jones about 
600 in his twenty. 

Prior was a Cambridge man and was educated at the 
Perse School in that town. He matriculated in 1854 at 
the age of twenty, became a Scholar in 1856, was twelfth 
Wrangler in 1858, elected Fellow in i860. Assistant Tutor 
in i86r, Tutor fiom 1870 to 1886. 



He was not a profound mathematician or an ardent 
reformer, but no one perhaps did more to increase the 
gaiety of the High Table. It is very difficult to describe 
how this was done. His talk was quite spontaneous, he 
rattled away and now and then burst out with something 
quite unexpected and often very funny. It emptied 

From unsuspected ambuscade 
The very Urns of Mirth. 

A very characteristic example was once when Mr Oscar 
Browning was complaining that he did not know what to 
do with his books, they were growing so fast ; Prior 
suggested to him that he should try reading them. Mr 
Thomely, in his delightful Cambridge Memories, ascribes this 
to Dr. Thompson, Master of Trinity, but I have heard 
the story told from time to time in Trinity for forty years 
and it has always been assigned to Prior. The style, too, 
is Prior’s and not the Master’s. 

(He had a very quick wit, which sometimes extricated 
him from difficulties which he had got into in his lectures 
on mathematics, 'j^n one occasion, when lecturing on 
statics, he attacked a problem on finding what the tension 
in a string would be under certain conditions. He began 
it some time before the end of the hour, but had not 
finished it by then. He put the blackboard carefully 
away, brought it out at the beginning of the next lecture 
and went on with the problem. After some Htde time he 
said to the class, “ At last we have got to the equation 
which wiQ give us T, the tension in the string ”. When 
he had worked at it a Httle longer, the equation he had 
found turned out to be 


This would have disconcerted many lecturers, but Prior 


rose to the occasion and said, “ Well, gentlemen, this at 
any rate shows that my arithmetic was correct.” ) 

In his rooms in the Old Court, which had been at one 
time the College hbrary, he had some good pictures, and 
fine pieces of old furniture and one of Chantrey’s busts of 
Sir Walter Scott. Towards the end of his life he lived 
in the house in Trumpington Road, on the outskirts of the 
town, which has since developed into the Evelyn Nursing 
Home. He still, however, kept on his rooms, but made 
very little use of them. 

He was a good judge of wine and a very useful member 
of the committee which has to select the wine to be bought 
by the College. Sampling these is by no means as pleasant 
as might be expected. The College buys the wine soon 
after it has been bottled and lays it down to mature 
Some of these young wines, especially the champagnes and 
clarets, were very nasty, and the better the vintage the 
nastier they were. I remember that some Chiteau Latour 
1874 was so astringent that it was undrinkable for many 
years, but in the end became the finest claret I ever drank 

Prior died at his house on the Trumpington Road m 
October 1918. He left his estate (subject to a life interest) 
to the College, unhampered by any conditions. This 
bequest has proved very useful as it has enabled the College 
to support some desirable objects which it could not 
owing to limitations imposed by the College statutes' 
have done out of Corporate Revenue. 

Henry Jackson 

No one was more associated with Trinity College m the 
minds of many generations of its leading men than Henry 

289 u 


Jackson. If two of these met after leaving Cambridge 
his name was more likely to crop up than that of any other 
Don, and he was the one they were most likely to call 
upon if they came to Cambridge. It was he who made 
a very important addition to the proceedings connected 
with our Commemoration of Benefactors, by giving a 
party which began after the dinner in Hall and the 
speeches were over. To this, which was held in two 
large lecture-rooms thrown into one for the occasion, he 
invited all the guests at the dinner, and in addition to these 
a large number of undergraduates. The guests at the 
dinner included some undergraduates, scholars, prizemen 
and a few others asked for special reasons, but it was not 
possible to find room in the Hall for more than a fraction 
of those we should like to have had with us. Jackson 
went round the College a day or two before Commemora- 
tion leaving cards of invitation to his party on very many 
undergraduates who had not been invited to the dinner. 
At the party there was smoking, whist, speeches, songs and 
whisky. He generally managed to get speeches out of 
some of the distinguished guests, and I have heard there 
Cabinet Ministers singing comic songs. There were clay 
pipes on the tables, and Jackson flitted about the room 
with a cigar-box in his hand. The party lasted until 
the small hours of the morning, and sometimes, I 
beheve, he took the few who were left at 2 or 3 o'clock 
over to his rooms, and kept the proceedings up for another 
hour or two. 

Jackson came to live in College in 1890, when his wife, 
who was in bad health, had been advised to live in a nulder 
climate than that of Cambridge. His rooms were in 
Nevile's Court on the North Side, and on the staircase 
nearest the Library. They were the ones I had just vacated 


on my marriage in 1890. Here in a sense he kept open 
house, for he never sported the oak when he was m his 
rooms. It was his custom to invite those who went to 
the Combination Room to take wine after dinner, to 
adjourn to his rooms to smoke and talk ; and very 
interesting the talk often was. He was an academic Dr. 
Johnson, quite as emphatic, though perhaps not so epigram- 
matic, as the “ Great Lexicographer His hospitality 
was not confmed to the older members of the College, and 
he welcomed the Bachelors of Arts and the undergraduates, 
and did much to establish fiiendly relations between the 
reading undergraduates and the older members of the 

His lectures on ancient philosophy were an outstanding 
feature in the teaching given in the College, After 1871, 
and until 1882, all candidates for the Classical Tripos were 
expected to show some knowledge of ancient philosophy. 
In this period Jackson's lectures were attended by some 
seventy or eighty students. Two large lecture-rooms 
were, for these as for his party, thrown into one, and he 
lectured with his back against the niche which divided 
the two rooms. His lectures were attended not only by 
Trinity men, but by the great majority of the classical 
students in the University. When in 1882 the Classical 
Tripos was altered by the addition of a second part, in 
which candidates could specialise in literature and criticism, 
philosophy, history, archaeology or philology, candidates 
could get a First Class by obtaining distinction in anyone of 
these subjects. As philosophy was no longer compulsory, the 
number attending his lectures naturally went down, but he 
still attracted the most able classics m the University. His 
influence was shown by the fact that the number of Trinity 
men who obtained distinction in philosophy in Part 11 


was, in the ten years following the change, greater than 
the number who obtained distinction in all the other 
subjects put together. He was a great teacher ; though 
he produced no magnum opus himself, he trained pupils 
who did, and these will probably be his most permanent 
memorial. He gave unstinted assistance to his pupils and 
his friends in the preparation of their books. Dr. Parry, 
in his Life of Jackson, gives a list of twenty-seven volumes 
which were dedicated to Jackson by pupils and friends, with 
warm acknowledgments of the great assistance he had 
given them. 

He took a great interest in University and College 
politics, and was a member of the Council of the Senate 
of the University, and also of the Council of Trinity 
College, for many years. He had, soon after getting his 
Fellowship, been most active in attempts at reform, spent 
a good deal of time in support of abohtion of rehgious 
tests for Fellowships, the abolition of compulsory Greek, 
the admission of women to the University and many other 
reforms. He took a prominent part in debates, both in 
the Senate House and at College meetings ; he was vigorous 
and outspoken in these, and sometimes ruffled the temper 
of those who did not agree with him. 

He succeeded Jebb as Regius Professor of Greek in 1906, 
but continuous bad health and the war interfered seriously 
with his professorial work. He received the Order of 
Merit in 1908. 

Perhaps the best expression of the feelings with which 
he was regarded in Trinity are to be found in an address, 
written by Professor Housman, and presented along with 
a copy of Porson’s tobacco-jar, by the Master and Fellows 
to him on his eightieth birthday. “ In Trinity, in Cam- 
bridge, in the whole academic world and far beyond it, 



you have earned a name on the lips of men and a place in 
their hearts to which few or none in the present or the 
past can make pretension. And this eminence you owe 
not only or chiefly to the fame of your learning and the 
influence of your teaching, nor even to that abounding 
and proverbial hospitahty which for many a long year has 
made your rooms the hearthstone of the Society, and a 
guest-house in Cambridge for pilgrims from the ends of 
the earth, but to the broad and true humanity of your 
nature, endearing you alike to old and young, responsive 
to aU varieties of character or pursuit, and remote from 
nothing that concerns mankind.” 

Henry Sidgwick 

Henry Sidgwick was a very outstanding member of 
the College from 1855, when he came up as a Freshman, 
until his death in 1900. As an undergraduate he had a very 
distinguished career ; he won the Craven Scholarship for 
Classics (the blue riband of University scholarships) in his 
second year. In 1859 he was Senior Classic, first Chan- 
cellor's Medallist and 33rd Wrangler in the Mathematical 
Tripos. He was an “ Apostle ” ' and President of the 
Union. He was elected to a Fellowship at his first try in 
i 859> 2nd appointed Assistant Tutor in ^e same year. At 
first he lectured on Classics, but after a short time, at the 
request of the College, he lectured on Moral Sciences. In 
1869 he resigned his Fellowship and Assistant Tutorship, as 
his religious opinions had changed since he had signed the 

I For an account of die society called the Aposdes, see Henry Sidgwick : 

A Memoir, by Arthur Sidgwick and Eleanor Mildred Sidgwick. Mac- 
millan, 1906. 



declaration that he beheved the doctrines of the Church 
of England, on his admission to a Fellowship ten years 
before. As he did not do so now, he thought it was his 
duty to resign his Fellowship. This action hastened the 
abohtion of rehgious tests in the College, for in the 
following year the motion “ That the Master and Seniors 
take such action as may be necessary in order to repeal all 
rehgious restrictions on the election and conditions of 
tenure of fellowships at present contained in the Statutes ”, 
was passed by the requisite two-thirds majority of the 
Fellows. The College did all in its power to retain him at 
Trinity : they elected him to a Lectureship in Moral and 
Pohtical Science and also to an Honorary Fellowship. 
After the passing of new Statutes in 1882 he was re-elected 
to an ordinary Fellowship. He was one of the most 
brilliant talkers of his time. Lord Bryce said his talk “ was 
like the sparkling of a brook whose ripples seem to give 
out sunshine”.^ I should think he was, in the opinion of 
most people, the most brilhant in Cambridge, and Leshe 
Stephen brackets him with the very eminent mathema- 
tician H. J. S. Smith, who was a Professor of that subject 
at Oxford, and whose epigrams for many years dehghted 
many people. One of them was about an editor of the 
scientific journal, Nature, who was sometimes accused of 
being cocksure about many things : it was, “ X fads to 
recognise the difference between the Author and Editor 
of Nature 

Sidgwick had a shght stutter which, whether by accident 
or design, became much more pronounced just before the 
point he was about to make ; this brought the point out, 
as it were, with a bang and made it much more effective. 
He often took part in discussions at meetings of the Fellows 
* Henty Sidgwick, p. 319. 



when suggested changes came under consideration. His 
speeches were a ver^" enjoyable intellectual treat, but they 
did not, I think, have much effect on the division. He was 
sometimes accused of sitting on the fence, but it was rather 
that he kept vaulting over it from one side to the other, 
giving arguments at one time in favour of the proposal, 
and following them with others against. Thus, whatever 
a man’s opinion might be, he got new arguments in its 
favour and voted as he had intended. 

The relation between the University and Colleges was 
profoundly changed in 1882 by the recommendations of 
the University Commission, which came into force in 
that year. They required the Colleges to pay annually a 
certain proportion of their incomes, to be fixed by the 
Commissioners, to the University. The percentage was 
graduated according to the wealth of the College : it could 
not be less than four nor greater than twenty-one per cent. 
A great deal of trouble had been taken over fixing this, and 
though it demanded substantial sacrifices from the Colleges 
it was not by most people regarded as unreasonable, con- 
sidering the urgent need of the University for money. It 
brought, however, into conflict more clearly than had ever 
been done before, the claims of the University and College. 
To most members of the University the College made by 
far the stronger appeal. At that time the majority of the 
members of the University had made very few contacts 
with it. When they matriculated they had to pay a fee 
to the Registrary, and at the various University examina- 
tions for their degree they might catch sight of their 
Examiners, or they might come into contact with the 
University Proctors, but tax-coUectors, Proctors and 
Examiners are not promising material for exciting ardent 


afFection. On the other hand, they owed to their Colleges 
a dehghtful home, their salaries, pleasant society, in many 
cases their teaching, for the lectures on classics and mathe- 
matics were at that time given by College Lecturers in 
College lecture-rooms. Again, in not a few cases it was a 
scholarship given by the College that had made it possible 
for them to come to Cambridge at all. All these things 
made their affection for the College much warmer than 
that for the University, and made them opponents to any 
changes which would seriously affect the prosperity of the 
College. It was not very long, too, before it became 
apparent that the great and rapid increase in the number 
of the new subjects for which the University, if it were 
to maintain its efficiency, would have to provide new 
Professorships and new laboratories, would make its 
income even when supplemented by the amounts con- 
tributed by the Colleges still quite inadequate. The most 
obvious way to increase the income of the University was 
to demand more from the Colleges, and many were afraid 
that it would not be very long before an attempt was 
made to do this. As Sidgwick was probably the most 
conspicuous of those who put the needs of the University 
before those of the Colleges, there were a good number 
who thought that everything he proposed had something 
lurking inside it, which would make it easier to extract 
money from the Colleges, and they voted against it. 
Fortunately, however, soon after the beginning of this 
century the University began to receive a succession of 
very handsome bequests and donations, and these, aided by 
a liberal grant from the Government, have put the finances 
of the University in such a good position that it has been 
quite unnecessary to ask for any increase in the contribu- 
tion from the Colleges. The income of the University 


from all sources has increased firom about ^60,000 in 1900 
to ^212,000 in 1930. It is not a very wild hypothesis to 
suppose that this has been to a large extent due to the 
important and very interesting discoveries which have been 
made in the University, and Cambridge may be quoted as 
an example of the practical results which come from 
Research for its own sake. 

The University now takes an enormously greater share 
in the teaching of undergraduates than it did thirty years 
ago. Now practically all the lectures to Honours students 
are given by University Lecturers in University buddings. 
It now, to its great advantage, plays in the student’s life 
a part comparable with that played by his CoUege. 

Sidgwick himself was a very generous benefactor of the 
University, and his gifts were aU the more valuable since 
they were often given on occasions when without them 
some important work done by the University would have 
had to be given up, or the opportunity of securing the 
services of some especially qualified teacher missed. Thus 
he gave money to continue the teaching of Indian Civil 
servants which was in danger of being given up, for 
securing the services of F. M. Maitland as a Reader in Law, 
for establishing a Professorship of Mental Philosophy, and 
for the erection of the Physiological Laboratory. Thus 
they were spread over all departments of University work. 

He gave work as well as money to the University. 
He served for some years on its Council and on the 
General Board. What was perhaps the most important 
work of his hfe (apart from that done as a Professor and 
writer on Philosophy) was that done in connection with 
Women’s Education. This is not the place to go into 
detad ; suffice it to say that he was the leader and most 
energetic worker in the movement which, starting in 1870 


with lectures to students living near Cambridge, had by 1 8 8o 
grown to Newnham College with a Hall of Residence, 
now Sidgwick Hall, in fine grounds and with eighty-five 
students, and that in i88r it was granted the privilege that 
its students should be admitted to the Honours Examina- 
tions, and the places they took in the examinations 
indicated in the class list ; and that after 1880 he and Mrs 
Sidgwick carried on the work with unabated activity and 
success. This work will secure him a prominent place in 
the list of pioneers in Education. 

Another subject on which he spent an immense amount 
of time and work was Psychical Research. He began 
taking an interest in such subjects when an undergraduate, 
for then he joined a society called the Ghost Society, 
founded by Archbishop Benson when he was at Cam- 
bridge, and of which it is beheved Dr. Westcott was 
Secretary, for the investigation of ghost stories. Accounts 
of abnormal experiences such as hallucinations, premoni- 
tions, phantasms of the dead and living and those occurring 
at spirituahstic seances were published from time to time, 
but no one troubled to test the evidence in support of them. 
By 1882 two eminent men of science. Sir William Crookes 
and A. R. Wallace, had expressed their behef in Spiritual- 
ism, but by scientific men in general such subjects were 
regarded as “ untouchables ; anyone touching them 
would lose caste. 

This was most unsatisfactory, for if even a very 
minute fraction of the things reported were true, the results 
were of transcendental importance and would revolu- 
tionise our ideas about physical as well as spiritual things. 
The Psychical Society was foimded largely through the 
zeal and energy of Professor W. F, Barrett in 1882 to in- 
vestigate questions of this kind; and Sidgwick consented 



to be its first president. He was an ideal president for such 
a society, absolutely fair and unbiassed and critical. The 
Society welcomed the communication of accounts of 
abnormal occurrences and then proceeded to test their 
evidential value. This involved an immense amount of 
correspondence. Sidgwick says in his diary that Mrs 
Sidgwick had gone away on a visit taking with her looo 
scripts on phantasms of the dead. It also led to many bitter 
disappointments. One night he writes in high spirits in 
his diary about the joy of discovery, as he thinks he has 
got conclusive evidence that afternoon of the reaUty of 
thought transference at a sitting he has had with a medium 
in Liverpool. .Another sitting the next morning proved 
that he had been deceived and that the results were 

This work has not been wasted. To put its claims at 
the very lowest it is surely a great thing to have created 
an organisation for collecting and testing these abnormal 
phenomena and thereby to go far to ensure that no genuine 
ones will escape discovery, 

I never heard anything more impressive than the speeches 
made at a meeting held at Trinity Lodge on November 26, 
1900, for the purpose of establishing a memorial to him. 
There were many speeches, aU of them good and all 
remarkable for the depth of the feelings they expressed. 
James Bryce and Professor Dicey spoke of the esteem in 
which he was held at Oxford, and said that there was no 
one in Cambridge who had had such intimate relations 
with that university ; his old pupils, F. M. Maitland and 
James Ward, spoke of what they owed to his teaching and 
the influence he had had upon their lives ; the Bishop of 
Bristol (G. F. Browne), who was for a long time the leader 
of the Conservative party in the University and therefore 


generally opposed to his policy, spoke of the good work 
Sidgwick had done in the development of Local Lectures 
and Examinations ; old friends like Dr. Butler, Leshe 
Stephen and Sir Richard Jebb told us of his triumphs as an 
undergraduate. What impressed me more than anything 
else was a sentence in the speech made by Canon Gore, 
who, balanced precariously on the kerb of the fireplace 
and apparently obHvious of all the surroundings, said, 
“We talk in a famifiar way about the World, the Flesh 
and the Devil ; one could not know him without thinking 
that neither the World, the Flesh nor the Devil had any 
place in him or about him.” 

James Ward 

James Ward, who succeeded Henry Sidgwick as 
Lecturer in Moral Science at Trinity College, had had a 
very varied experience before joining the College. He 
had been articled when very young to an architect in 
Liverpool. He soon gave that up and went for six years 
to Spring Hill College, a college for the training of Con- 
gregational ministers. He then became the minister at the 
Congregational Chapel in Cambridge, but resigned after 
twelve months in consequence of a change in his religious 
opinions. He was elected to a Trinity Scholarship in 1 873 , 
and when in 1875 Trinity offered a Fellowship in Moral 
Science, he was the successful candidate in an excep- 
tionally strong field. The other candidates were F. M. 
Maitland, who became Downing Professor of the Laws of 
England; Arthur Lyttelton, who became Master of Selwyn; 
and WiUiam Cunningham, who became a well-known 
authority on Pohtical Economy, and advocated, with great 


ability, views which, were then heretical but which re- 
sembled in many respects those which are now prevalent. 
He became later Vicar of Great St. Mary’s and Archdeacon 
of Ely. All the candidates had been at the top of the list 
in one year or another of the Moral Sciences Tripos. 
Ward was the only one in that class in his year. He was 
elected to a Lectureship in Moral Science in Trinity 
College in i88i, and to the Professorship of Mental 
Philosophy and Logic in 1893 . He was a Tutor of Trinity 
from 1896 to 1897. This was a post for which he was not 
well fitted. He had not become an undergraduate himself 
until he was thirty, and knew very Httle about, and perhaps 
had but httle sympathy with, the views and pursuits of the 
normal undergraduate. 

After his election to a Fellowship he worked in the 
Physiological Laboratory under Michael Foster, who 
thought so well of him that he said a good physiologist 
was lost when he devoted himself to philosophy. Ward 
even published a paper in the Journal of Physiology. He 
was a severe critic of his own work as well as that of other 
people. He was never satisfied with what he had done 
and kept putting off pubhcation in the hope of making it 
better. His best work was done on commission. Thus 
Robertson Smith, the editor of the Encyclopaedia Britannica, 
persuaded him to write the article on Psychology, which at 
once established his reputation as a psychologist of the very 
first rank. Again, his Naturalism and Agnosticism and The 
Realm of Ends, which won for him the same position in 
other branches of philosophy, were the result of his under- 
taking to give the Gifford Lectures in the Universities of 
Aberdeen and St. Andrews respectively. His conversation, 
though it did not sparkle with epigrams and paradoxes 
like that of some of his contemporaries, was q^uite as 


impressive. One could not talk with him on a serious 
subject without recognising that he had a mind of quite 
exceptional acuteness and had thought deeply on every- 
thing he spoke about. He was an excellent field naturahst, 
and a walk with him in the country was most interesting 
and instructive, for he recognised and had something new 
to tell one about nearly every bird or flower that came in 
the way. Though he was rather an austere man he had 
many warm friends in Cambridge, and the admiration 
and respect which was felt for him was expressed by 
the presentation to him on his eightieth birthday of 
his portrait by McEvoy. 

J. McT. E. McTaggan 

John McTaggart Elhs McTaggart came up to Trinity 
from Chfton in 1885. He was alone in the first class of the 
Moral Science Tripos in 1888, and was elected to a Fellow- 
ship at Trinity in 1891. He then paid a long visit to New 
Zealand, where in 1894 he did the wisest thing he ever did 
in his life by marrying Miss Margaret Bird. As an under- 
graduate he was prominent among the “ intellectuals ” of 
his year. He was an “ Apostle ” and a successful speaker 
at the Union, where he was President in 1890. In 1897 
he was made Lecturer in Moral Science at Trinity College, 
and held this post until he retired after twenty-five years’ 
service in 1923 . In addition to his lectures to students of 
Moral Science, he gave a course of one lecture a week 
intended for those who were not specialising in philosophy 
but who wished to get a general idea of what it was about. 
This course was extraordinarily successful ; it was attended 
by large audiences and he repeated it year after year. These 


lectures probably made many take some interest in philo- 
sophy who without them would never have thought 
about it. His lectures and writings were exceptionally 
clear : he never left you in doubt as to what he meant. 
His witticisms and paradoxes made them sparkling and 
exciting ; they were very pleasant to Hsten to or to read. 

Mr H. G. Wells in The New Machiavelli introduces him 
under the name of Codger, and describes very graphically 
and accurately his appearance, his gait and other charac- 
teristics, but for all this the Codger of the novel is not 
McTaggart. Codger is like one of Mr Wells’ Martians, 
all brain and no heart, one who does not love or hate or 
grieve, whose interests are confined to unravelling the 
secrets of Hegel. This is not McTaggart. He, besides 
being a HegeHan, was an excellent man of business and 
affairs, and enjoyed this kind of work. His love for his 
old school, his college and his country was intense. I 
never knew anyone who had a greater love or veneration 
for Trinity, or one more anxious to keep up its old customs. 
He never missed a meeting of the Fellows and always took 
an active part in the discussion. He served on the Council 
of the College and on numerous committees ; he dined 
regularly in Hall, and kept up the old custom of going after 
Hall to the Combination Room, even when, as sometimes 
happened, he was the only one who did so. 

When the war came McTaggart grasped at every 
opportunity of helping England to win. To save Cam- 
bridge from being bombarded by Zeppelins it was desir- 
able to keep it as dark as possible, so a corps was formed 
to patrol the streets at night and see that all lights were 
dimmed. No one was more zealous or persistent in this 
work than McTaggart, and no one, as I know to my cost, 
had such a severe standard of dimness. The efforts of 



himself and his colleagues were successful, for Cambridge 
was never hit by a bomb though many fell not far away. 
He felt very strongly that it was everyone’s duty to do ^ 
they could to help to win the war, and he had no toleration 
for those who shirked this work, or still worse, thought it 
their duty by their speeches and writings to incite others to 
do so. This led to his breaking off friendly relations with 
some of his oldest friends. 

McTaggart was a man who made up his own mind on 
political matters and was not in the pocket of any political 
party. In University matters he was a reformer ; he 
supported the abohtion of compulsory Greek, and was 
strongly in favour of the admission of women to the 
University. In politics he foimd it difficult to know who 
to vote for. The old-fashioned Whigs seemed to repre- 
sent his views, but where are the Whigs to be found? 
He was a very strong Free Trader. His views on this 
were much like those of the “ Manchester School ” of 
Cobden and Bright — ^no interference with trade either 
by tariffs or by regulations about wages : but now there 
are no Free Traders who do not hold opinions which he 
detested more than he did tariffs. 

He managed to hold opinions which are not usually 
reconciled. He was not a Christian, and yet for meta- 
physical reasons a firm believer in Immortality. He was 
also a strong supporter of an Established Church, because 
it excited the antagonism of Dissenters and so weakened the 
influence of religion on the policy of the country, which 
in his opinion was a very desirable thing. McTaggart 
was a lover of ceremonial and ritual ; he seized every 
opportunity of wearing the scarlet gown of a D.Litt., 
and took a great interest in drawing up the Hst of occasions 
on which Trinity should exercise its privilege of flying the 



Royal Standard. He was the least athletic able-bodied man 
I ever met. He detested games, and when at Clifton, 
where games were compulsory, had frustrated the attempt 
to make him play football by lying flat on the ground 
and refusing to get up. 

W. W, Rouse Ball 

W. W. Rouse BaU, who for nearly fifty years did 
excellent work for the College both in administration and 
in teaching, and who bequeathed to it one of the largest 
legacies it has ever received, was bom in London in 1850. 
He came up from University College, London, to Trinity 
as a Minor Scholar in 1870, and was Second Wrangler 
and 1st Smith's Prizeman in 1874. was made a Fellow 
of the College in 1875, and after a short career at the Bar 
he returned to Trinity as Lecturer in 1878, and lived in 
Cambridge for the rest of his life. He held the Lectureship 
until 1905, and was a Tutor of the College from 1893 to 
1905. Rouse Ball took a deep and very genuine interest in 
his pupils, and did much to establish social as well as official 
relations with them. He often asked them to dinner, and 
built a billiard-room and a squash-racquets court for their 
amusement. He also took pains to keep in touch with 
them after they left Cambridge. He had supported 
warmly the scheme for “ Old Boys' " dinners, which was 
put into force in 1 8 89. He took an interest in their sports : 
he was treasurer of the ist Trinity Boat Club and wrote its 
history, and gave a challenge cup to be held by the winners 
of the Inter-CoUegiate Athletic Sports. BaU was a good 
chess player, and had represented Cambridge in the first 
Oxford and Cambridge Chess Match in 1873, His 

305 X 


Mathematical Recreations, of which ten editions have been 
published, discusses arithmetical and geometrical puzzles, 
magic squares, the problem of the 15 schoolgirls, squar- 
ing the circle, trisecting an angle, mazes (he had a maze in 
his garden), cryptograms, ciphers, etc. Anything of the 
nature of a puzzle or an ingenious toy had a great fascina- 
tion for him. He had a large collection of those apphca- 
tions of science to frivolous purposes which can be bought 
for a few pence from the trays of hawkers in London and 
Paris. To encourage conjuring he founded the “ Pentacle 
Club ” in Cambridge, which gives annual performances 
of an ambitious kind. He was also interested in cat’s 
cradles, which have an ethnological importance, and gave 
a lecture on them at the Royal Institution. His Short 
History of Mathematics, which had a very large circulation, 
is a most interesting book. It is very well written, and 
the mathematics is leavened by accounts of the idiosyn- 
crasies and escapades of the mathematicians. For a long 
time he had the intention of writing a biography of Sir 
Isaac Newton, and had collected a considerable amount of 
material for it. He was prevented by the pressure of other 
work from completing this, but he embodied part of it in 
his very able and interesting Essay on the Genesis and History 
of Newton s ‘ ‘ Principia ”. He had formed a very fine collec- 
tion of portraits of mathematicians. Rouse Ball was inter- 
ested in the history of Trinity College as well as of mathe- 
matics : he knew not only its official history as expressed 
in minutes of its Governing Body, but, better than any- 
one else of his time, its more intimate history, the 
gossip of the Combination Room, epigrams and verses like 
those of Porson and Mansel, and the ephemeral Hterature, 
such as is contained in the fly-sheets which had been issued 
when some burning question was dividing the College. 



He published a very short History of Trinity College in 
Dent's series of histories of Cambridge Colleges. In 
collaboration with Mr Venn (now President of Queens' 
College, Cambridge) he edited four volumes containing 
the names of those admitted to the College between 1546 
and 1900. 

Mr Ball did a great amount of administrative work 
for the College : he served on its Council, with only four 
years' interval, from 1888 to 1925, and was its Secretary 
from 1891 to 1894. Besides this, he was a member 
of many other important Committees of the College. 
He was an excellent man of business, had very sound 
judgment, never wasted any time at a meeting, stated 
a case very clearly and fairly, and nothing could ruffle 
his courtesy. This was a great help in soothing down 
acrimonious discussions. A Vice-Chancellor, who had to 
preside at the meetings of the University Finance Com- 
mittee at a time when it contained three pugnacious 
Bursars as well as Ball, told me that it was only Ball's efforts 
which prevented the Committee becoming a bear-garden. 

The funds of Trinity College and also of the University 
owe much to Mr Ball’s ability in financial matters. When 
his father died he inherited a considerable sum of money : 
he determined to make it the nucleus of a fund for the 
promotion of education and research, and for this purpose 
he made it into a trust, the trustee being an important 
financial house in New York. According to the provision 
of the Trust, Ball was to have the control of the invest- 
ments and the power to withdraw money from the Trust, 
provided the sum withdrawn was devoted to education or 
research. He devoted, he told me, unremitting attention 
and much labour to the investment of the funds of the 
Trust, and was so successful that, at the time of his death, 



the Trust had increased to many times its original value, 
even to many times what its value would have been if the 
interest had just been allowed to accumulate without 
change of investments. There had been no great coup, 
but just a steady flow of small increments. By his will he 
estabhshed new Professorships in Mathematics and in Law 
at both Cambridge and Oxford, and left substantial sums 
to the Cambridge University Library and also to the 
Library of Trinity College. The residue, which was the 
major part of the estate, went to Trinity College. The 
sum received from this legacy has only been exceeded once, 
and that by a relatively small amount, in the history of the 
College. It is unique in that it was due largely to his 
working for many years with the set purpose of increasing 
the power of the College to fulfil one of its most important 
fimctions — the promotion of research. He had in his life- 
time made gifts to the College, one for a fund to enable 
students to meet medical expenses, and another for a travel- 
ling studentship in mathematics, and had founded in the 
University the Rouse Ball Lectureship in Mathematics. 

He was a good friend of mine for nearly fifty years, and 
I am grateful to him for many kindnesses, much help and 
wise counsel. 

Reginald St. John Parry 

Reginald St. John Parry came up to Trinity with a 
JMinor Scholarship in 1876. He was 2nd Classic in 1880, 
was elected to a Fellowship in 1881 and to an Assistant 
Lectureship in Classics in the same year. The College 
was his home until he died, as he never married. His 
life was spent in the service of the College : he had held 
every major College appointment, and was Vice-Master 


from 1919 until his death in 1935. He took a large part 
in the administration of the College, he served many years 
on the College Council and on innumerable Committees. 
For a long time he was Secretary of the Livings Committee 
and took a leading part in the very difficult business of 
fmdmg suitable men to fill vacant College livings. He was 
a Canon of Southwell Cathedral. Perhaps the most im- 
portant work he did for the College was through the 
“At Homes” he held on Sunday evenings in Term time. 
He was very cathohc in his invitations to these; he was 
especially anxious to include undergraduates who had not 
many friends in Trinity before they came up. He was an 
excellent host, and managed to get his guests to speak 
freely to each other, and many men owe to these At 
Homes friendships which they regard as among the best 
of the good things they got at Trinity. Meetings of this 
kind help to minimise one of the disadvantages of a large 
College where men may not meet each other so frequently 
as they do in a smaller one. Parry knew a large number 
of the undergraduates in residence and kept in touch with 
many of them after they went down. One of the attrac- 
tions to our guests at the Old Members’ dinner was the 
chance it gave them of meeting him again. When 
Henry Jackson’s health failed, he took on “Jackson’s” 
party after Commemoration. Parry was a prominent 
supporter of Reform in both College and University 
questions ; in fact his opinion on these was generally 
much the same as Jackson’s. He took a share in Univer- 
sity as well as College Administration, served for several 
years on its Council, and was for a time Chairman of the 
University Press Syndicate. He took a great interest in 
“ Adult Education”, and in 1930 received an address signed 
by Mr Stanley Baldwin and a large number of distin- 



guished people, expressing their profound sense of the 
invaluable services which he had rendered for over thirty 
years to the cause of Adult Education. 

Srinivasa Ramanujan 

Few, if any. Fellows of Trinity can have had a more 
romantic career than Ramanujan. His parents were 
Brahmins, Hving in the Madras Presidency and in poor 
circumstances. When he was seven years old he went to 
the High School at Kumbakonam and remained there 
until he was sixteen. He showed quite remarkable mathe- 
matical abihty, and in his last year, after he had access to 
Carr’s Synopsis of Pure Mathematics, which contains a hst 
of mathematical formulae without any proofs, he revelled 
in finding the proofs for himself. He matriculated at the 
University of Madras and studied at the Government 
College at Kumbakonam, gaining a scholarship awarded 
for proficiency in mathematics and Enghsh. His Univer- 
sity career was a failure. He spent all his time on mathe- 
matics, even that in the lecture-room when he was 
supposed to be Hstening to lectures on other subjects. 
Naturally he faded to pass in an examination which 
included these subjects. Another attempt resulted in 
another failure. He kept on, however, working at 
mathematics and entering the results he obtained in his 
note-books. In 1909 he got married, and it was necessary 
for him to obtain some post to provide a Hvelihood. 
Owing to his failure to get a degree this was difficult, but 
he finally obtained a subordinate post, with a salary of 
30 rupees a month, in the Madras Port Trust Office. 
Though the salary was so small, it was, as things turned 


out, the turning-point in his career, for the manager of 
the Company was a mathematician and took a great 
interest in Ramanujan. On the advice of his friends, 
Ramanujan wrote to Mr G. H. Hardy, a mathematical 
Lecturer and Fellow of Trinity College, giving a hst of a 
number of theorems he had discovered. Some of these 
were not new, a few were not true, but there were some 
so important that Mr Hardy was convinced that Ramanu- 
jan had mathematical abilities of the highest order, and he 
started enquires to see if steps could not be taken to enable 
him to come to Cambridge. Ramanujan was asked if he 
would go to England, but since he would lose caste by 
doing so, he said no. Another Fellow of Trinity, Mr (now 
Sir) Gilbert Walker, who was the head of the Indian 
Meteorological OfSce, happened to visit Madras and was 
shown some of Ramantyan’s work. He wrote to the 
University of Madras suggesting that steps should be 
taken to enable Ramanujan to devote the whole of his 
time to mathematics. In consequence of this the Uni- 
versity, with the consent of the Government, gave 
Ramanujan a special scholarship of 75 rupees per month. 
Soon after this another Fellow of Trinity appeared on the 
scene, in Mr Neville, who was invited to give. a course of 
lectures on mathematics at Madras University. When 
Mr Neville got to Madras he set to work to persuade 
Ramanujan to alter his decision about coming to England. 
He found that he himself was not unwilling to do so — ^the 
difficulty was with his mother, who would not give her 
consent, and he would not come without it. One morn- 
ing, however, she said she had had a dream in which she 
saw her son in a big hall in the midst of a group of Euro- 
peans, and that the goddess Namigiri had commanded her 
not to stand in his way. After this, all was easy. The 


University of Madras granted him a scholarship of ^^$0 
a year for two years, tenable in England, and Ramanujan, 
having arranged that his mother should receive 6o rupees 
per month out of this, sailed for England in March 1914, 
reached Cambridge in April, was admitted to Trinity 
College, and given an exhibition of ^60 per annum to 
supplement his scholarship from Madras. When he 
arrived in Cambridge it was found, as might have been 
expected from his training, that, while he had a profound 
knowledge of some part of mathematics, there were 
many parts of which he was quite ignorant, and some of 
these were important in connection with the parts of 
mathematics in which he was interested. He was said 
also to have a very vague idea of what constituted a 
mathematical proof. After a few years’ teaching by Mr 
Hardy, these defects were remedied without checking the 
flow of his original work. Ramanujan pubhshed a number 
of important papers which led to his election to the Royal 
Society in the spring of 1918, when he was barely thirty. 
He was the first Indian to be elected and he was elected 
the first time his name was in the hst of candidates, which 
is somewhat unusual. In the same year he was elected to 
a Fellowship at Trinity College, which entitled him to an 
income of about for six years unconditionally. 

His health broke down early in 1917, and he went into 
a nursing home, first in Cambridge, and afterwards in 
Wells, Matlock and London. Late in 1918 he got dis- 
tinctly better, and as it was thought that his illness might 
have been due to the difference between the cHmate and 
food of Cambridge and India, he returned to India early 
in 1919. This was, however, of no avail, for he died on 
April 20, 1920. 

A volume containing his collected papers, edited by 


G. H. Hardy, P. V. Seshu Aiyat and B. M. Wilson, was 
published by the Cambridge University Press m 1927. 
In addition to this there were in his note-books statements 
without proofs of a large number of theorems. These 
have been worked over by several eminent mathemati- 
cians, who have succeeded in proving the correctness of a 
good many of them, and thereby greatly strengthened the 
verdict of Professor Hardy that in his own field he was 
unrivalled in his day. His method, however, was not the 
normal one in which the theorem arises out of the proof ; 
no proof, no theorem. It is possible, however, to imagine 
other ways of proving theorems. Suppose, for example, 
a mathematician dreamt that he had discovered a new 
theorem, if he remembered it when he awoke he might 
test it by seeing if it gave the right result in a great number 
of special cases. This is the method of “ trial and error ” ; 
the great difficulty in this method is to get something to 
try ; there are an infinite number of things which might 
be tried, and xmless we had something to guide us the 
chance of choosing the right one would be infinitesimal. 
It need not require a dream to act as a guide. One who, 
like Ramanujan, had made a long and intense study of a 
particular branch of mathematics might almost uncon- 
sciously have been led to recognise certain features, such as 
the absence or presence of certain arrangements of the 
symbols in the theorems known to be true, and would 
instinctively reject a theorem in which these did not occur. 
He would, by long experience, have acquired an instinct 
by which he could distinguish between theorems which 
were possible and those which were impossible. Then, if 
he had the imagination to think of a theorem which would 
satisfy the test, and the industry and power of calculation 
required to verify it, he might arrive at theorems which he 



could not prove. There are several instances of mathe- 
matical theorems which are beheved to be true but have 
never been proved. Perhaps the most famous is the for- 
mula given by Gauss for the number of prime numbers 
(i.e. numbers which, like 2,3,5,7, ii . . are not divisible 
by any other number), which are less than a given number 
N ; Gauss’ formula was tested for integral values of N up 
to a thousand millions, and was found to give the right 
result. This was universally accepted as overwhelming 
evidence of its truth, though no formal proof had been 
discovered. Professor Littlewood has shown, however, 
that it must ultimately fad when N is greater than a certain 
number. This number, however, is so prodigious that it 
would be beyond the power of human effort to count by 
trial the number of primes. Thus Gauss’s rule may con- 
sole itself by thinking that though it may lapse from 
rectitude it never does so when it can be found out. 

A. E, Housman 

A. E. Housman became a Fellow of Trinity in 1911, 
soon after he had been elected to the Professorship of Latin 
in Cambridge University. After his election to a Fellow- 
ship he made the College his home, hving in rooms in 
College and dining regularly in the College Had. His 
rooms were for many years on Staircase K, Whewell’s 
Court, up many flights of stairs. To avoid these he moved 
into ground-floor rooms on Staircase B, Old Court, a few 
months before he died. 

He joined, in 1919, a dining-club of resident Cambridge 
graduates which met once a fortnight in term time, and of 
which I was a member, and he was very seldom absent 



from their dinners. I had thus for nearly twenty-five 
years many opportunities of meeting him, and after this 
long experience I think that his silence and aloofiiess were 
very much exaggerated in some of his obituary notices. 
It is true that from time to time he had fits of silence and 
depression ; but these were rare, surprisingly so, in view 
of the pessimism of much of his poetry. He usually, in 
my experience, talked freely and, as might be expected, 
incisively. He held strong opinions on many subjects and 
expressed them strongly, and he was not fond of strangers. 
I always found him excellent company, and was very glad 
when I could sit next to him. 

His appearance and his tastes were very different from 
those popularly attributed to poets ; he had nothing of the 
poet about him, except the poetry. He was careful about 
his dress, which was not marked by any eccentricity, his 
hair was short. He looked much yoxmger than his years. 
I was much perturbed one morning when reading The 
Times to see that it was his seventieth birthday, for I had 
not sent him, as I should have liked to do, my good 
wishes on such an important event. He took my excuses 
in very good part, and said that I was not the only one who 
had misjudged him, for a few days before, when he was 
walking along a country lane, a farm hand who was 
driving a cart, coming up from behind, had called out 
“ Hey, you lad, get out of the way He liked good food 
and good wine and was a connoisseur in both ; in fact he 
was for many years a member of the committee which 
chooses the wine for the College. Housman took much 
interest both in wild flowers and in gardening : he was a 
member of the Garden Committee for many years, and 
for a part of the time its Secretary. This is a post of con- 
siderable responsibility, as the secretary is responsible for 



the supervision of the garden and the gardeners, and for 
seeing that the recommendations of the committee are 
carried out. He was a very active and useful member of 
the committee. He held very decided views, which in 
general seemed to me quite sound, about the desirability 
or otherwise of changes which might be suggested. He 
liked flowers to have bright and definite colours, and was 
very contemptuous of what are called in florists’ catalogues 
“ art shades ”, and which he called muddles. 

Though he was quite indifferent to distinctions and 
had refused one which many regard as the greatest which 
could be conferred upon them, there was one which I 
think he did appreciate : it was to have had a dish, 
Barbue Housman, which is a speciality of a famous Paris 
restaurant, named after him. The dinners which he gave 
as a member of the Dining Club had, like everything he 
did, the air of distinction. There was always some dish 
which few, if any, of his guests had met with before, and 
over which he had taken a good deal of trouble to instruct 
the College cook in all the details of its preparation. All 
the wine was good, and there was pretty sure to be some 
of special interest or rarity. He recognised, too, the 
virtues of beer. Has it ever been exalted to such a height 
of dignity as in 

Malt does more than Milton can 
To justify God’s ways to man ? 

In the Leshe Stephen lecture, “ The Name and Nature 
of Poetry ”, he describes the way his poems had been 
made : in this, beer plays a part. They were not made by 
a sad mechanic exercise, but “ there would flow into my 
mind, with sudden and unaccountable emotion, sometimes 
a line or two of verse, sometimes a whole stanza at once, 
accompanied, not preceded, by a vague notion of the poem 


wliich they were destined to form part of”. He found 
that this flow was helped if he had a pint of beer at 
luncheon : this acted as a sedative to the brain, and made 
it more likely to respond to abnormal influences (we may 
compare it to the trance which precedes hypnotic pheno- 
mena). To Housman, poetry was something which ex- 
cited certain emotions ; it seemed to him more physical 
than intellectual, and its production differed from that of 
prose by being passive and involuntary rather than active. 
It came as it were of itself and not by conscious thought. 

I remember asking him once if he thought it was possible 
that Tennyson's “ Crossing the Bar ” could, with its ex- 
quisite phrasing, have been composed, as has often been 
stated, in its final form in the forty minutes or so while 
the poet was crossing from the mainland to the Isle of 
Wight. He said he thought it was quite possible, for if 
the poet had one of these fits of inspiration the right words 
woiid come of themselves. 

Though he could write dignified and vigorous prose 
such as few could equal, he disliked doing so ; it did not, 
like his poems, come spontaneously, and he had to spend 
much work and time before he got it into a form which 
satisfied him. It required a great deal to do this, as he was 
very fastidious. He was never satisfied with a thing that 
was good only in parts. In his lecture, Housman quoted 
passages from Shakespeare as examples of supreme poetry, 
but I have heard him say that it gave him no pleasure to 
read a play of Shakespeare's from beginning to end, for 
though some parts were magnificent, there were others so 
slovenly that the effect of the whole was disagreeable. 

Housman was not only a poet, he was also Professor of 
Latin, and at the conclusion of his lecture on poetry he 
said that was his proper job. I am quite incompetent to 



form any opinion of his merits as a classical scholar, but 1 
know that many high authorities regard him as the greatest 
England has produced since Bentley ; even laymen can 
verify that he was as vigorous as that great man in his 
criticism of those who differed from him. Housman did 
once wander into a subject which is at any rate closely akin 
to mathematics. He studied astrology when he was pre- 
paring his edition of Manihus, and learned how to cast 
horoscopes. Astrology is closely connected with the 
motion of the planets, and thus involves ideas which are 
sufficiently mathematical to scare off the great majority of 
classical scholars. His lectures were, I am told, confined 
to the text of the author he was considering and he did not 
discuss its Hterary merits. The one exception, I beheve, 
was when he lectured on Horace, when he gave a trans- 
lation of Odes, iv. 7, into Enghsh verse, and was so much 
moved by it that his eyes filled with tears. 

He continued to give his lectures even after his health 
broke down, sometimes coming from the nursing-home to 
the lecture-room, and going back there as soon as the 
lecture was over. 

I saw him on the day he gave his last lecture. He was 
terribly ill and must have had invincible determination to 
lecture in such a state. He was taken to the nursing-home 
the next day, and died there on April 30, 1936. The 
funeral was in the College chapel, and the hymn was one 
he had written himself and sent a year before to the Dean 
of Chapel, asking that it might be sung at his funeral. 

I have not space enough to give an account of more 
than a minute fraction of the number of Trinity men I 
have known during my sixty years’ residence in Cam- 
bridge. The few I have given have been in the main 



those who had very long connections with the College and 
were known to many generations of Trinity men, or were 
connected with events of exceptional interest. I feel, how- 
ever, that I should be underrating my debt to the College 
if I left without mention, however brief, some others 
whose friendship I owed to my connection with Trinity. 

G. F. Cobb, who had been alone in the First Class of 
the Moral Sciences Tripos in i86i, became Junior Bursar 
in 1 869. He was a good musician and his settings to music 
of several of Kipling’s Barrack-Room Ballads became very 
popular. When he was a young man he was what would 
now be called an Anglo-Cathohc, and wrote a book called 
the Kiss of Peace, advocating closer union with the Roman 
Church. This aroused the ire of another Fellow of the 
College, Sedley Taylor, who was in the same year as 
Cobb and was also a good musician, but he was also a 
mathematician and could not forgive the treatment of 
Galileo, so he wrote a reply called the Kick of War. He 
wrote also an excellent book, Sound and Music, and invented 
an instrument called a phoneidoscope, in which soap 
films showed beautifully coloured patterns when musical 
notes fell upon them. He was an excellent teller of good 
stories and no one enjoyed them more than himself ; 
after telling the story he rubbed the palms of his hands 
vigorously together and beamed on all around him. He 
was interested in social questions and found the money 
for providing periodic inspection of the eyes of children 
in Cambridge schools. He left a large bequest to the 
College, and an important road in Cambridge is called 
the Sedley Taylor Road. 

His namesake, H. M. Taylor, who had been Mathe- 
matical Lecturer and Tutor, was remarkable for the 
resolution and success with which he fought against the 



disabilities imposed by blindness -which came upon him 
when he was middle-aged. He continued to take an 
active interest in municipal affairs. He became Mayor 
and fulfilled efficiently all the duties of that office. He 
even, after he was blind, brought out for the Pitt Press an 
edition of Euclid. It is remarkable that R. D. Hicks, a 
very learned Greek scholar and a Fellow and Lecturer 
of the College, also became blind, from the same cause, 
“ detachment of the retina ”, as Taylor, and only a few 
months afterwards. 

A. W. Verrall, a lecturer in Classics and at one time 
Tutor, was a very briUiant and stimulating lecturer, and 
delighted large audiences by his ingenuity in suggesting 
emendations to obscure passages in classical authors. His 
colleagues were not always convinced of the soundness of 
some of these, but it is certain that he was exceptionally 
successful in arousing the interest of his hearers, which is 
one of the most important things a lecturer can do. He 
held the Clark lectureship in English Literature for one 
year, and the lectures he gave were exceptionally successful. 

F. J. H. Jenkinson, also at one time a lecturer in Classics 
and later the University Librarian, and in addition an 
excellent field naturalist, was one of the best beloved 
Trinity men of his generation. There is an admirably 
vivid and intimate biography of him by his brother-in-law, 
Dr. H. F. Stewart. 

J. P. Postgate, a distinguished Latin Scholar, was also a 
Classical Lecturer in Trinity from 1884 to 1909. He was 
one of the pioneers in introducing what was then the new 
pronunciation of Latin. I was once a victim of this. 
When I was admitted to the Professorship, I had by the 
regulations to make a declaration in Latin before the Vice- 
Chancellor. Postgate, who was a great friend of mine, 


asked me to use the new pronunciation. I said I had no 
prejudices one way or the other, and if he would teach it 
me I would use the new. I began doing so, but I had 
not gone very far before the Vice-Chancellor, who was a 
mathematician, stopped me, and said that by the regula- 
tions of the University I must make the declaration in 
Latin. So I had to begin again, and pronounce it as I 
should have done if I had been left to myself. 

James Stuart, who played a very prominent part in 
University affairs between 1870 and 1890 and was the 
originator of important developments of University activi- 
ties, became a Fellow in 1867 and was a Lecturer in 
Mathematics from 1868 to 1875, when he became Pro- 
fessor of Mechanism. He was a pioneer in the establish- 
ment and organisation of lectures and classes outside 
Cambridge, and it was his enthusiasm and persistence 
which induced the University to undertake this work. 
It was very successful ; in 1913 lectures were given in 
forty-nine places outside Cambridge. When he was 
elected to the Professorship of Mechanism, he began by 
taking steps to obtain a workshop and drawing office for 
the instruction of his students, and these, on a very- 
modest scale, were estabhshed by the end of 1881. Mr 
J. A. Fleming, now Sit Ambrose Fleming, F.R.S., was 
appointed Demonstrator. The number of engineering 
students rapidly increased, and when he resigned the 
Professorship in 1890 and was succeeded by Professor 
Ewing, they were numerous enough to justify the estab- 
Hshment of an Engineering Tripos. Thus it was Stuart 
who started the Engineering School in Cambridge. 

George Howard Darwin, the son of Charles Darwin, 
was elected Fellow of Trinity in 1868 ; his Fellowship 
expired in 1878, but he was re-elected in 1883 when he 

321 Y 


became Plumian Professor. Except for a short time after 
his first election to a Fellowship, he worked uninterruptedly 
in Cambridge on questions such as the genesis of the moon, 
the theory of tides, periodic orbits, all alike involving 
mathematical investigations which were not only difficult 
but very lengthy, and required great patience as well as 
great sl^. This may be regarded as the apotheosis of 
arithmetic, as so much of it consisted of arithmetical 
calculations. Lord Kelvin quickly recognised the import- 
ance of his work, encouraged him to go on with it, and a 
warm friendship sprang up between them. Darwin him- 
self was very generous in the encouragement he gave to 
young men, as I can testify by personal experience. His 
work was recognised by many scientific societies both at 
home and abroad. He was President of the Astronomical 
Society and received their Gold Medal. He was President 
of the British Association when it met in South Africa. 
He received the Royal and the Copley Medals from the 
Royal Society and it is an open secret that he would have 
been invited to accept the Presidency in succession to 
Sir Archibald Geikie, who would retire on December i, 
1913. His unfailing courtesy and his interest in many 
branches of science would have made him an ideal Pre- 
sident. But it was not to be. His health had been bad 
firom the spring of 1912, and in the autumn it was found 
that he was suffering from a mahgnant disease from which 
he died at the age of sixty-seven on December 7, 1912. 

John Wilhs Clark, who was a Fellow from 1858 to 
1868, was a very conspicuous figure in University hfe for 
more than fifty years. He was a native of Cambridge, 
where his father was Professor of Anatomy. He had so 
many and such varied activities, and had held so many 
offices, including that of Registrary of the University, that 


it is impossible in a short notice to give any adequate 
account of them. Fortunately this is not necessar)% for 
there is a most entertaining, interesting, sympathetic and 
intimate biography written by his close friend, the late 
Sir Arthur Shipley, F.R.S., Master of Christ’s College. 

John Newport Langley, F.R.S., graduated firom St. 
John’s College but was elected to a Trinity Fellowship in 
1877, and was a Lecturer from 1884 to 1903, when he 
succeeded Michael Foster as Professor of Physiology. By 
his own fundamental discoveries on the nervous system and 
also by the good work done by his pupil, he increased the 
already great reputation of the Cambridge Physiological 
School, and it was under his active supervision that the 
new Laboratory was erected. He was also for long a most 
efficient Editor of the Journal of Physiology. He had many 
interests and accomplishments; among other things he was 
one of the best skaters in England in the old style, which 
was more swanlike ” than that now in vogue, though 
not so acrobatic. He was a good man of affairs, a good 
man on a committee and a good companion. 

Walter Morley Fletcher, who became a Fellow in 
1897, a Lecturer in 1899 and was Tutor from 1905 to 1915, 
was a pupil of Langley’s, and there were points of resem- 
blance between them, especially in the width of their 
activities. Thus Fletcher, while an undergraduate, got 
First Classes in both parts of the Natural Sciences Tripos, 
and also his “ Blue ” for athletics. Besides his scientific 
activities, Fletcher took an interest in art. He was very 
active and helpful m regard to schemes involving altera- 
tions in the structure or appearance of the College. He 
helped Langley in the design of the new Physiological 
Laboratory, and the undergraduates in planning extensive 
alterations to the Pitt Club. Throughout his life he took 


a great interest in athletics and, indeed, in sport of all 
kinds. Nis most important work was done after he ceased 
to be Tutor in 1915. In that year he was appointed 
Secretary to the Medical Research Council, a body with a 
large grant from Government which had just been formed 
for the promotion of medical research in this country. 
The members of this Council had to develop the methods 
by which this could best be done, and in such a case as this 
a great deal depends on the energy and powers of organisa- 
tion of the Secretary. Fletcher was eminently successful, 
and by the time of his death in I934, the Medical Research 
Council was stated by an authority as high as that of the 
President of the Royal Society to have brought medical 
research in this country to a level comparable to that 
in any other. He had a wide circle of warm friends of 
all sorts and conditions ; he was a Fellow of the Royal 
Society and was made a knight in 1918. 

Anthony Ashley Bevan was elected a Fellow in 1890. 
He remained a Fellow until his death, but refused to receive 
any dividends. He was made a Lecturer in Hebrew and 
Oriental Languages in 1887, and Lord Almoner’s Professor 
of Arabic in 1893. Hebrew and Arabic were not the 
only languages in which he was proficient. He had been 
educated in Lausanne and spoke French and German as 
fluendy as he did English. Whenever there was a guest 
in HaU who could not speak any Enghsh we tried to 
arrange that he should sit next Bevan. He had charming 
manners, tinged with a courtliness which was almost French. 
Though there were but few students taking Hebrew or 
Arabic, he managed to make contact with many under- 
graduates, and often invited them to his rooms after HaU 
and gave them very hot chocolate to drink. He was a very 
generous man and a liberal benefactor of the CoUege. 



tntin the bust by F. Derwent WoikI in the Jhbrary oflVinity College, 


Discharge of Electricity through Gases; The 
Discovery of the Electron; Positive Rays 

I T was a most fortunate coincidence that the advent of 
research students at the Cavendish Laboratory came at 
the same time as the announcement by Rontgen of his 
discovery of the X-rays. I had a copy of his apparatus 
made and set up at the Laboratory, and the first thing I 
did with it was to see what effect the passage of these rays 
through a gas would produce on its electrical properties. 
To my great dehght I found that this made it a conductor 
of electricity, even though the electric force apphed to the 
gas was exceedingly small, whereas the gas when it was 
not exposed to the rays did not conduct electricity unless 
the electric force were inaeased many thousandfold. It 
required an electric force of about 30,000 volts per centi- 
metre to make electricity pass through air at atmospheric 
pressure when not exposed to the rays, while a minute 
fraction of this was sufiScient when the rays were going 
through it. This was a matter of vital importance for the 
investigations on the passage of electricity through gases, 
a problem at which I had been working for many years. 
Until the rays were discovered the only ways of making 
electricity pass through a gas were either to apply very 
great electric forces to it, or else to use very hot gases such 
as flames. In either case it was exceedingly difficult to get 
anything like accurate measurements. The results were 
apt to be very capricious, apparently depending upon 



causes which it was very difficult to locate. We know 
now that these two phenomena are the most complex and 
difficult in the whole range included in the subject of 
conduction of electricity through gases. To have come 
upon a method of producing conductivity in the gas so 
controllable and so convenient as that of the X-rays was 
hke coming into smooth water after long buffeting by 
heavy seas. The X-rays seem to turn the gas into a 
gaseous electrolyte. Indeed, many of the difficulties which 
had been met with in the early stages of the conduction 
through hquid electrolytes had been met with in those of 
the conduction through gases. One of these difficulties 
in the case of liquid electrolytes was to see how the 
positively and negatively charged atoms in a molecule 
of the electrolyte could be separated from each other by 
the very small electric forces which are adequate to pro- 
duce conduction. The attraction between these oppositely 
charged atoms is of the order of 1,600,000,000 volts per cm., 
and yet a force of a fraction of a volt per centimetre is 
sufficient to make an atom with a positive charge appear 
at one electrode and one with a negative charge at the 
other. To explain this Grotthus, in 1805, introduced the 
idea that the molecules with their + and - atoms formed 
themselves into chains, like iron filings when acted upon 
by a magnet and that the + atom in one molecule went 
close to the - atom of the adjacent molecule in the way 
indicated in the figure. AB, CD, EF represent molecules. 

(4?) (CD) (EF) 

The attraction of the positive charge of B on the atom A 
is balanced by the repulsion due to the negative charge 
on C, which is close to B. Each atom, except those at the 
end, has a close neighbour of opposite sign, so that the two 


balance each other. Thus the forces exerted by all the 
atoms except those at the end of the chain are balanced, 
and the forces on those at the end correspond to the forces 
between two particles separated by the length of the chain, 
instead of by the distance between two atoms in one mole- 
cule. A very short chain would be all that was needed to 
make the attraction between the oppositely charged atoms 
at the ends so small that an infinitesimal electric force 
would be sufficient to separate them. The view ^now 
generally accepted — introduced by Arrhenius, that the 
molecules in a solution are dissociated by the action of the 
solvent, and not by that of any external electric force, has 
made the introduction of the conception of Grotthus 
chains unnecessary. A difficulty of the same type was met 
with in the study of the passage of a current of electricity 
through a gas under the action of an electric force between 
electrodes immersed in it. There was very strong evidence 
to show that in this case there was decomposition of some 
of the molecules when the electric force exceeded about 
30,000 volts per cm. for air at atmospheric pressure ; this 
force, though considerable, is infinitesimal in comparison 
with the 1,000,000,000 volts per cm. required to separate 
one charged atom from another in a molecule. How, then, 
are the positively and negatively charged particles sepa- 
rated ? One way which suggests itself is the formation 
of Grotthus’ chains. In the Hght of what we know now 
it seems that in a gas, in which there are no free charged 
particles, and which is protected against anything passing 
through it from outside, there would be no separation of 
charged particles unless the electric force had the Wger 
value. The separation of the positively and negatively 
electrified parts of a molecule is not regarded now as due 
to the electric force pulling the two parts asunder in a kind 



of electrical tug-of-war. The role of the electric force is 
rather to give to an extraneous charged particle so much 
energy that when it strikes against a molecule one part of 
the molecule is knocked away from the other by the colli- 
sion. This produces two new free charged particles ; 
these imder the electric field will acquire enough energy 
to ionise other molecules and so the number of charged 
particles produced will increase in geometrical progression. 
The energy that was in the electric field is used up in giving 
energy to the charged particles. It is a very common 
experience that when the gas has been very carefully dried, 
and the walls of the vessel in which it is contained and the 
electrodes carefully freed from absorbed gases, it is very 
difficult to get the first spark to pass through it, but when a 
spark has passed, succeeding sparks pass quite easily. This 
is because each spark produces many charged particles, and 
some of these linger in the gas long after the spark has 
passed. I have known more than one case when to get 
the first spark to pass it was necessary to increase the electric 
force to such an extent that, when it did pass, the current 
was so great that it fused part of the apparatus. When the 
gas is traversed by Rontgen rays the smallest electric force 
is sufficient to send a current through it. It does for the 
gas much what is done by the solvent for the salts dissolved 
in Hquid electrolytes. 

I started at once, in the late autumn of 1895, on working 
at the electric properties of gases exposed to Rontgen rays, 
and soon foimd some interesting and suggestive results. 
The conductivity produced by the rays does not reach its 
full value the moment the rays start, nor does it disappear 
the moment they stop. There is an interval when the 
gas conducts though the rays have ceased to go through it. 
We studied the properties of the gas in this state, and found 


that the conductivity was destroyed when the gas passed 
through a filter of glass wool. 

A still more interesting result was that the conductivity 
could be filtered out without using any mechanical filter 
by exposing the conducting gas to electric forces. The 
first experiment shows that the conductivity is due to 
particles present in the gas, and the second shows that these 
particles are charged with electricity. The conductivity 
due to the Rontgen rays is caused by these rays producing 
in the gas a number of charged particles.* 

Another interesting point we found when studying 
the relations between the potential difference between 
the electrodes and the current through the gas, was that 
though when the potential difference was small, the current 
was proportional to the potential difference, as it is in 
conduction through metals and electrolytes ; yet, as the 
potential difference increased, the current did not increase 
in proportion. The increase got smaller and smaller as 
the potential difference increased, until the current became 
constant, and did not increase again until the potential 
difference was so large that it would have produced a 
current without the aid of the rays. This is just what we 
should expect if the current is carried by charged particles 
produced by the rays ; when the current passes these 
come up against the electrodes, lose their charges, and can 
no longer carry the current. The current passing through 
the gas is proportional to the number of charged particles 
which strike against the electrodes in one second. As 

* The photographs taken by C. T. R. Wilson many years after the 
discovery of the conductivity produced by Rontgen rays show that the 
primary effect of these rays is to eject electrons moving at high speeds from 
the molecules hit by the rays. These swift electrons eject other electrons 
from the molecules they hit. Thus the negatively elecnhfied particles start 
as electrons which finally get attached to molecules. 



the charged particles are produced by the rays, it is evident 
that the number which disappear in one second cannot be 
greater than the number produced by the rays in that time. 
Thus the current, when the charged particles are produced 
by the rays, must have a Hmit proportional to the intensity 
of the rays. The measurement of this hmiting current or 
saturation current, as it is usually called, is a very convenient 
method of measuring the intensity of the Rontgen rays. 

The disappearance of the conductivity after the rays 
are stopped is due to the combination of the positive and 
negative ions to form a neutral particle, which plays no 
part in carrying the current. If there are respectively 
and Hi positively and negatively charged particles in unit 
volume of the gas, the number of collisions occurring in 
unit volume per unit time is proportional to nitiz. Let 
it be equal to cuntfi^, ^ is called the coefficient of recombina- 
tion, and may depend on the pressure, temperature and 
character of the gas. The current through the gas is due 
to the motion of charged particles, and will depend upon 
the velocity they acquire under the action of the electric 
force. It follows from the kinetic theory of gases that 
the velocity of a particle moving through a gas is, when 
the pressure is not very low, proportional to the force 
acting upon it. If X is the electric force and e the charge 
on the particle, the force on the particle is Xe ; let feiX, 
kJL be the velocities of the positively and negatively 
charged particles respectively ; fei and kz are called the 
mobilities of the positive and negative ions respectively. 

Supposing, as we are led to suppose by the facts which 
have just been stated, that the current is carried by elec- 
trified particles which are continually being produced by 
the Rontgen rays, and that these are then driven against 
the electrodes by the electric force acting in the gas, we 


can find a differential equation which expresses the relation 
between the current through the gas and the potential 
difference between the electrodes. This, except when the 
potential difference is very small, is not nearly so simple 
as that expressed by Ohm’s Law. The relation involves 
the coefficient of recombination a, the mobilities kz and 
^2, and q, the number of ions per second produced by 
the rays. The latter is easily determined, since it is meas- 
ured by the maximum current that can be made to pass 
without sparking through the gas; a, ki, h, are the funda- 
mental quantities on which the relation depends, and for 
the next three or four years much of the work of the 
Laboratory was concentrated on studying these. Ruther- 
ford, who had completed his work on the detection ot 
electric waves by a magnetic method, determined the 
value of a for different gases and made many determina- 
tions of the mobilities of the ions by methods of his own 
devising. Zeleny also made many important experiments 
on the mobihty of ions in different gases by finding the 
electric force which would just force an ion against 
current of gas of known velocity, and showed that the 
mobility of the negative ion was often greater than that 
of the positive. He fotmd that this difference was greater 
in carefully dried and purified gases than in damp or 
impure gases. Experiments made many years later by 
Franck show that in certain cases a very small amount of 
impurity produces an enormous decrease in the mobility 
of the negative ion. Thus, in pore helium the mobility 
of the negative was loo times that of the positive, and the 
addition of a trace of oxygen reduced this ratio to i*2. In 
the pure helium the electrons ejected by Rdntgen rays do 
not attach themselves to the atoms of helium, and so remain 
electrons with a high mobility. If there is any oxygen 



present the electrons are captured by the oxygen molecules. 
The carriers of the negative electricity are then ponderous 
molecules instead of Hght electrons . T o wnsend also worked 
on the diffusion of ions. Indeed, after a few years’ work 
the properties of the gaseous ions were known with greater 
precision than the properties of the ions in liquid electro- 
lytes, which had been studied for a very much longer 
time. An immense amount of work leading to many im- 
portant discoveries has been done since these experiments 
were made, but I think the workers in the Cavendish 
Laboratory may claim to have been the pioneers. 

During the period 1896-1900, 104 papers were pub- 
hshed by workers in the Cavendish Laboratory. I have not 
space even to give their titles : one, however, I must refer 
to. It was the one in which C. T. R. Wilson showed that 
an electrified body lost its charge in dust-free air, when he 
had arranged the experiment so that a defect in the insula- 
tion of the body would diminish the leak. This occurred 
when there were no Rontgen rays passing through the gas, 
and when it was shielded by thick metal from radiation 
from outside. It was the study of this “ residual leak ”, so 
called because every known source had been eliminated, 
that led to the discovery of the “ cosmic rays ”. It is one 
of the romances of science that the study of these very 
minute, and, what might seem trivial, effects should have 
led to results which threw much hght on a subject of such 
great importance as the structure of the atom. 

Discovery of the Electron 

The research which led to the discovery of the electron 
began with an attempt to explain the discrepancy between 


the behaviour of cathode rays under magnetic and electric 
forces. Magnetic forces deflect the rays in just the same 
ways as they would a negatively electrified particle moving 
in the direction of the rays. 

A Faraday cylinder placed out of the normal path of 
a thin beam of cathode rays does not receive any charge of 
electricity, but it receives a copious negative one when 
the beam is deflected by a magnet into the cylinder. This 
would seem to be conclusive evidence that the rays carried 
a charge of negative electricity, had not Hertz found that 
when they were exposed to an electric force they were not 
deflected at all. From this he came to the conclusion that 
they were not charged particles. He took the view which 
was held by the majority of German physicists that they 
were flexible electric currents flowing through the ether, 
the negative electricity flowing out of the cathode and the 
positive into it, and that they were acted upon by magnetic 
forces in accordance with the laws discovered by Ampere 
for the forces exerted on electric currents. 

Such currents would give a charge of negative elec- 
tricity to bodies against which they struck. They would 
be deflected by a magnet in accordance with Ampere’s 
laws. They would not be deflected by electric forces. 
These are just the properties which the cathode rays 
were for a long time thought to possess. 

It ought to be pointed out that Goldstein, who for 
more than thirty years worked indefatigably on cathode 
rays and made many important discoveries about them, 
obtained in 1880^ an effect which we see now must have 
been due to an effect produced by electric force on the 
rays. He used a tube in which there were two cathodes 
side by side, and he observed that when only one cathode 

^ Eine neue Form elektrischer Ahstossung. Berlin 1880. J. Springer. 



was in action the cathode rays from it were not in the 
same direction as when both cathodes were in action 
simultaneously. The deflection was in the direction which 
indicated a repulsion between the two beams of rays. 

My first attempt to deflect a beam of cathode rays was 
to pass it between two parallel metal plates fastened in- 
side the discharge-tube, and to produce an electric field 
between the plates. This failed to produce any lasting 
deflection. I could, however, detect a sHght flicker in 
the beam when the electric force was first applied. This 
gave the clue to what I think is the explanation of the 
absence of the electric deflection of the rays. If there is 
any gas between the plates it will be ionised by the cathode 
rays when they pass through it, and thus produce a supply 
of both positively and negatively electrified particles. 
The positively charged plate will attract to itself negatively 
electrified particles which will neutraHse, in the space 
between the plates, the effect of its own positive electrifica- 
tion. Similarly, the effect of the negatively electrified 
plate will be neutralised by the positively electrified 
particles it attracts. Thus charging up the plates will not 
produce an electric force between them ; the momentary- 
flicker was due to the neutralisation of the plates not being 
instantaneous. The absence of deflection on this view is 
due to the presence of gas — to the pressure being too high 
— thus the thing to do was to get a much higher vacuum. 
This was more easily said than done. The technique of 
producing high vacua in those days was in an elementary 
stage. The necessity of getting rid of gas condensed on 
the walls of the discharge tube, and on the metal of the 
electrodes by prolonged baking, was not reahsed. As this 
gas was hberated when the discharge passed through the 
tube, the vacuum deteriorated rapidly during the discharge, 


and the pumps then available were not fast enough to keep 
pace with this hberation. However, after running the 
discharge through the tube day after day without in- 
troducing fresh gas, the gas on the walls and electrodes 
got driven off and it was possible to get a much better 
vacuum. The deflection of the cathode rays by electric 
forces became quite marked, and its direction indicated 
that the particles forming the cathode rays were negatively 

This result removed the discrepancy between the effects 
of magnetic and electric forces on the cathode particles : 
it did much more than this, it provided a method of 
measuring v, the velocity of these particles, and also mje, 
where m is the mass of a particle and e its electric charge. 

The mechanical force exerted by an electric force X 
on the particle is equal to Xe and is in the same direction 
as X ; the mechanical force on the moving particle 
exerted by a magnetic force H is not in the direction 
of H, but at right angles to it, and it is also at right 
angles to the velocity of the particle ; if the magnetic force 
is at right angles to the direction of motion of the par- 
ticle the mechanical force is Heu. If the appHed electric 
force X is at right angles both to the velocity and to the 
magnetic force, the mechanical forces due to the electric 
and magnetic forces are in the same straight line, and by 
altering X and H can be made to balance each other, leav- 
ing the cathode particle undeflected. When this is the 
case Xe=Het', so that i;=X/H. As we can measure easily 
both X and H, this gives a simple method of finding p. 
When we have got v, we can get mje, for a magnetic 
force applied in the proper direction bends a thin pencil 
of cathode rays into a circle whose radius is mvjlle ; this 
can be measured, and hence by the magnetic deflection 



alone we can determine mvje. This had been done by 
Schuster ten years before I made my experiments. The 
magnetic deflection alone does not determine either v or 
mje. Schuster assumed that, before reaching the place 
where the deflections were observed, the cathode particles 
had made so many collisions with the particles of the gas 
through which they were passing, that they had been 
brought into statistical equilibrium with the surrounding 
gas, and had the same energy as molecules of the gas at 
the temperature of the discharge tube. On this assump- 
tion he came to the conclusion that the masses of the 
cathode particles were of the same order as the masses of 
the molecules of the gas through which they were passing. 
His argument would have been quite sound if the cathode 
particles were atoms or molecules of the gas, and when 
he foimd that on this assumption the magnetic deflection 
agreed with his observations, the evidence in favour of 
cathode particles being charged atoms or molecules seemed 
very strong. I did not see how to reconcile the sharp 
outline of a thin beam of cathode rays with the idea that 
its particles had made enough coUisions to bring them into 
statistical equilibrium with the surrounding gas, and it 
seemed to me necessary to measure directly either the 
energy or the velocity of the particles. I began by measur- 
ing their energy by allowing a pencil of the rays to fall 
through an opening in a Faraday cylinder which was 
connected with an electrometer. Inside the cylinder 
there was a thermopile which the particles heated up when 
they struck against it. The temperature to which the 
thermopile was raised in a given time was measured, and, 
since the heat capacity of the cylinder and its contents 
was known, the energy communicated in one second 
could be determined. If n is the mimber of cathode 


particles striking the thermopile per second, m the mass, 
e the electric charge and v the velocity of a particle, the 
energy, E, given to the thermopile per second is given 
by the equation B=^nmv^ ; Q, the charge given to the 
electrometer, is given by : from the magnetic 

deflection we get T, where T—ejmv : from these equations 
we find 

e 2ET^ 
m Q 

giving the value of elm in terms of quantities which can 
be measured. Another method I used was to balance the 
deflection produced by a magnetic force H against one 
produced by an electric force X. Then since 


another expression for ejm. 

Using one or other of these methods, I determined the 
value of ejm for different gas fillings of the tube, air, 
hydrogen, carbonic acid, but found that the value was the 
same for each of these gases ; the mean value for twenty- 
six experiments was 2-3 x 10^. The values of v varied 
in the different experiments from 2-3x10® to i-2Xio^® 
cm. j sec. 

These experiments were of an exploratory nature ; the 
apparatus was of a simple character and not designed to 
get the most accurate numerical results. It Vvas suffcient, 
however, to prove that e/m for the cathode ray particles 
was of the order 10^, whereas the smallest value hitherto 
found was lo'^ for the atom of hydrogen in electrolysis. 
So that if e were the same as the charge of electricity 
carried by an atom of hydrogen — as was subsequently 

337 z 


proved to be the case — m, the mass of the cathode ray- 
particle, could not be greater than one-thousandth part 
of the mass of an atom of hydrogen, the smallest mass 
hitherto recognised. It was also proved that the mass of 
these particles did not depend upon the kind of gas in 
the discharge-tube. These results were so surprising that 
it seemed more important to make a general survey of 
the subject than to endeavour to improve the determina- 
tion of the exact value of the ratio of the mass of the particle 
to the mass of the hydrogen atom. It was found then, 
when the aluminium electrodes which had been used in 
the first experiment were replaced by platinum or other 
metals, that no effect was produced on the value of e/m, 
nor did altering the kind of glass used for making the 
discharge-tube produce any change. 

I next tested electrified particles which had been pro- 
duced by methods in which no electric force had been 
apphed to their source. It is known that metals when 
exposed to ultra-violet hght give off negative electricity, 
and that metaUic and carbon filaments do so when in- 
candescent. I measured, by methods based on similar 
principles to those used for cathode rays, the values of 
e/m for the carriers of negative electricity in these cases, 
and found that it was the same as for cathode rays. 

After long consideration of the experiments it seemed 
to me that there was no escape from the following 
conclusions : 

(1) That atoms are not indivisible, for negatively 
electrified particles can be tom from them by the action 
of electrical forces, impact of rapidly moving atoms, ultra- 
violet light or heat. 

(2) That these particles are aU of the same mass, and 
carry the same charge of negative electricity from what- 



ever kind of atom they may be derived, and are a con- 
stituent of all atoms. 

(3) That the mass of these particles is less than one- 
thousandth part of the mass of an atom of hydrogen. 

I at first called these particles corpuscles, but they are 
now called by the more appropriate name “ electrons 
I made the first announcement of the existence of these 
corpuscles in a Friday Evening Discourse at the Royal 
Institution on April 29, 1897, of which an abstract was 
published in the Electrician^ May 21, 1897. It was pub- 
lished at length in the Philosophical Magazine for October 
1897. About the same time other investigations of m/e 
were published by Wiechert and Kaufinann, who obtained 
values which agreed fairly well with mine. They did 
not, however, make direct measurements of anything but 
the magnetic deflection of the cathode ray. This only gives 
mvje ; they did not make any direct measurement of v 
or of the energy fnv^j 2 at the place where they measured 
the magnetic deflection, but, like Schuster, estimated the 
energy by making assumptions about the connection be- 
tween the energy of the particle at the place where the 
magnetic deflection was measured, and the energy which 
it would acquire by falling through the potential difference 
between the electrodes in the discharge-tube. But whereas 
Schuster assumed that, by collisions with the molecules of 
the gas, the cathode particle had lost practically all the 
energy it had acquired from the electric field in the tube, 
Wiechert and Kaufmann assumed that it had lost none of 
this energy. 

It is not possible to estimate from the potential difference 
between the cathode and anode of the discharge tube the 
energy possessed by a charged particle at any point in its 
course without knowing more about the mechanism of 


the discharge than we do even at the present time. It is 
not even possible to determine the hmits between which 
this energy must He. Thus, for example, a charged 
particle starting from the cathode would ionise the gas 
through which it passed and produce other charged par- 
ticles. These again would produce other charged particles 
when energised by the electric field, and these again would 
produce other charged particles. These secondary particles 
would not acquire as much energy as they would have 
done if they had started from the cathode itself. Again, if 
charged particles are hberated from the cathode by the 
impact of radiation such as ultra-violet radiation or Ront- 
gen radiation of very short wave-length, which is known 
to be present in the discharge-tubes, the particles would 
start from the cathode with a considerable amount of 
energy, and their energy at any place would be greater 
than that due to the electric field. If negative particles 
were emitted from the cathode by the impact of positive 
ions, they might start with energy derived from these 
particles, and not from the electric field. Measurements 
of the magnetic deflection only give vx {tnje). To obtain 
the value of (tn/e) it is necessary to measure v, or some 
combination of (m/e) and v other than their product. 

The interpretation I put upon my results was quite 
different from that put by the German physicists on theirs. 
Kaufmann {Wiedemanns Annalen^ 6i, p. 552) interpreted 
the fact that the value of e/m does not depend on the kind 
of gas in the tube or on the metal used for the cathode as 
proving that the negatively electrified particles did not 
come out of either the gas or the metal. I took the view 
that all atoms contained these small particles, and that they 
could be knocked out of the atom by electrical means, by 
high temperatures or by Rontgen rays. 



At first there were very few who beheved in the existence 
of these bodies smaller than atoms. I was even told long 
afterwards by a distinguished physicist who had been 
present at my lecture at the Royal Institution that he 
thought I had been “ pulling their legs I was not 
surprised at this, as I had myself come to this explanation 
of my experiments with great reluctance, and it was only 
after I was convinced that the experiment left no escape 
from it that I pubhshed my behef in the existence of bodies 
smaller than atoms. There were, however, a few, I think 
Professor G. F. Fitzgerald was one, who thought I had 
made out a good case. I went on with my experiments. 
I determined m/e for the carriers of negative electricity 
emitted by metals exposed to ultra-violet hght ; it w^as 
the same as that for the cathode rays. I found also that 
this was true for the carriers of negative electricity given 
out by hot metals. I also determined the value of e for 
the electric charge carried by these negatively electrified 
particles, and found that it was the same as that carried by 
the hydrogen atom in the electrolysis of hquids. This left 
no doubt that the large value of e/m was due to the small- 
ness of the mass and not to the magnitude of the charge. 
I brought these results before the meeting of the British 
Association at Dover in 1899, when my great friend Pro- 
fessor J. H. Poynting was secretary of Section A, and I 
tbink I made a good many converts to these views. 

The Value of e 

The work of C. T. R. Wilson in the Cavendish Labora- 
tory on the formation of fogs suppHes a method for finding 
this. Aitken in 1880 discovered that whereas a cloud is 



produced in ordinary air, saturated with water vapour, 
when it is cooled by a very slight expansion of its volume, 
no fog is produced even by very considerable expansions 
when the dust is filtered out of the air. The drops of water 
require nuclei on which they can be deposited ; in ordinary- 
air these are supplied by the particles of dust which it 
contains. Wilson found that when the dust-j&ee gas which 
would not give a fog was ionised, and therefore contained 
both negatively and positively electrified particles, a fog 
was produced by an expansion too small to produce one 
in dust-free air, and that a fog would be produced on 
negative particles by an expansion less than that required 
for positive ones. Thus with certain expansions all the 
drops will be negatively electrified. 

Thus if the gas is ionised, say by radiation from radium, 
it will contain negatively electrified particles ; drops of 
water will be deposited on these by a supersaturation which 
is not sufficient to produce any drops when the particles 
are not electrified, or electrified only with positive elec- 
tricity. This discovery has been developed into a method 
which has had a profound influence on the recent study of 
atomic physics. 

If we supersaturate the gas by cooling it by a sudden 
expansion of known amount, we can calculate the lowering 
of temperature, and hence the difference in the amount of 
water required to saturate the air before and after expan- 
sion. This will be the amount of water deposited as drops 
on the negatively charged particle. These drops will fall 
down slowly under gravity. They will in consequence of 
the viscosity of the air fall with uniform velocity. This 
velocity depends on the size of the drops, which can be 
determined by Townsend’s method of measuring the 
rate at which they fall. We know the total quantity of 



water deposited on the drops, and since we know the 
quantity of water in each drop we can find at once the 
number of drops. 

If we drive by an electric force all the negatively 
electrified particles to a metal plate connected ^vith an 
electrometer, we can determine the sum of the charges 
on the negatively electrified particles ; and since the 
number of these particles is equal to the number of drops, 
we can determine the charge e carried by each particle. 
A simpler method was invented later by H. A. Wilson. 
We measure, in the same way as before, the size and there- 
fore the weight of the drop by observing the rate at which 
it falls. Then we apply an electric force X, which, if e 
is the charge on the drop, exerts an upward electric force 
Xe, so that if is the weight of the drop, the vertical 
downward force is xv - Xe. If we alter X until the drop 
remains like Mahomet’s coflSn at rest under the force, 
e=wjyi, which determines e. In practice it is better to 
measure the rate of fall under different electric forces, 
than to attempt to get gravity exactly balanced. 

The value of e given by these methods is, within limits 
of experimental error, equal to the charge carried by an 
atom of hydrogen in electrolysis ; thus the fact that ejm 
for these charged particles is more than a thousand times 
that for the atom of hydrogen, must be due to an abnor- 
mally small value of m and not to an abnormally large one 
of e. 

Number of Electrons in the Atom 

Since the mass of an electron is only about 1/1800 of 
that of an atom of hydrogen, unless there are hxmdreds of 
electrons m the atom they will not accoimt for more than 


a very small fraction of its mass ; it is therefore a matter 
of great interest to determine this number. This was 
first done at the Cavendish Laboratory in 1904 by 
measuring the scattering of X-rays when passing through 
a gas. X-rays behave like light waves of very small 
wave-length, and these on Maxwell’s Theory are accom- 
panied by electric and magnetic forces ; when these rays 
pass over an electron the electric forces will accelerate the 
electron. A charged body when accelerated gives out 
radiation, and the rate at which the energy of the radiation 
is emitted was shown by Larmor to be 2 e^fijsc, where e is 
the electric charge on the moving body, / the acceleration, 
and c the velocity of hght. If F is the electric force in 
the X-rays at the place of the charge, /=Fe/m, where m 
is the mass of the charged body ; the rate at which it is 
emitting radiant energy is thus 2e'^F^/3m^c. The energy in 
unit volume of a beam of light when the electric force is F 
is, on the Electromagnetic Theory, and the energy 

flowing through unit area per second is The energy 

is emitted from the electron at the rate times this, 

so that one electron per c.c. would scatter the fraction 
of the energy of the X-rays passing through a 
cubic centimetre. If an atom contained n electrons, then, 
one atom would scatter n times this fraction, provided the 
distance between them were considerable when compared 
with the wave-length of the X-rays, If two electrons were 
only a small fraction of this wave-length apart, they would 
act like a double charge with a double mass, and we see 
from the formula, would scatter four times as much as a 
single electron. Again, the formula will not apply unless 
the frequency of the X-rays is large compared with the 
frequency with which the electron would vibrate if dis- 
turbed from its position of equihbrium in the atom. 



When the preceding conditions are fulfilled, we see that 
when we have N atoms each containing n electrons in a 
c.c. of the gas, the energy in the scattered radiation will be 
(S-Tre^lsm^) Nn times that in the incident X-ray radiation. 

If we know the pressure of the gas we can, by Avo- 
gadro’s law, determine N, and if we measure the fraction 
of the incident radiation scattered, we can determine n, 
the number of electrons in an atom. This was done by 
Barkla for several gases, and he found that for these the 
number of electrons in an atom was approximately half 
the atomic weight, except for hydrogen where there was 
one electron in the atom. This is in accordance with the 
result of modem investigations on the structure of the 
atom. This would make the part of the mass of an atom 
due to the electrons a very small fraction of the whole 
mass, but the fraction would be much the same for atoms 
of different chemical elements. 

The expression for the scattering can be expressed very 
simply in terms of the radius of the electron. The mass 
m of an electron of radius a is given by the equation 
m— 2.6^1 2, a \ since the energy scattered by an electron is 
times the energy of the radiation passing through 
unit area, it is 677 times the energy falling on the area of 
the cross-section of the electron. 

On the quantum theory of light the scattering by elec- 
trons arises in a different way. When one of the photons 
in a beam of hght strikes against an electron it is deflected, 
and produces light in the direction in which it is deflected ; 
it will also lose energy, and since the frequency of the Hght 
is proportional to the energy, the frequency of the Hght 
will be diminished, and the wave-length increased. The 
dynamics of the coUision between photons and electrons 
have been worked out by A. H. Compton, who showed 



that it follows, from the principles of conservation of 
energy, that the increase in wave-length produced by a 
collision is independent of the frequency of the light and 
is 0-0243 A ; this is too small to be appreciable for ordinary 
light, but for very hard X-rays the effect is very marked. 
When there is no appreciable loss of energy at a collision 
the amount of scattering is much the same on either theory. 

Diffraction of Electrons: Electronic Waves 

It was not until 19 1 1, long after the discovery of X-rays, 
that it was proved that these rays could be diffracted ; 
there was strong evidence that they were light of very 
short wave-length, so short that it was infinitesimal in 
comparison with the distance between the rulings on an 
ordinary diffraction grating, so that these could not diffract 
the rays. In 1911, however, Laue had the brilliant idea 
that since a crystal consisted of a series of atoms arranged 
in regular order, it should act like a diffraction grating in 
which the intervals between the rulings were equal to the 
distance between neighbouring atoms, and would be able 
to produce diffraction effects for waves whose length was 
not very much less, or very much greater, than this dis- 
tance. Using crystals as diffraction gratings, he obtained 
diffraction effects with X-rays, and was able to measure 
their wave-length. 

Davisson and Germer in 1927 directed a beam of elec- 
trons at right angles to the face of a nickel crystal, and 
measured by an electroscope the number of electrons 
coming off in different directions. They found that the 
number of electrons in the scattered beam did not vary 
continuously with the angle of scattering, but that there 


were several directions in which the scattered electrons 
showed maxima of intensity, and that these directions 
corresponded to the direction of diffracted X-rays of a par- 
ticular wave-length . This wave-length, was in go o d agree- 
ment with an equation given by Prince Louis de Broghe : 

where h is Planck’s constant, and m and v the mass and 
velocity of the electron 

Two months after the publication of these results, my 
son. Professor G. P. Thomson, published photographs ob- 
tained by sending a beam of homogeneous cathode rays — 
ue. a beam where all the electrons had the same velocity 
— through a very t hin film of collodion. This showed 
a bright central spot due to electrons which had passed 
through without being deflected. Around this there were 
rings, and the diameter of these was in agreement with 
de Broghe’s equation. 

The chemical composition of collodion is too compli- 
cated and imcertain to allow of a test of the agreement of 
the experiment with theory, so Thomson tried very thin 
films of the various metals for which the dimensions of 
the lattices, formed by the atoms in the crystal, had been 
determined by experiment with X-rays. The first photo- 
graph pubhshed of the rings shown by thin gold is shown in 
Plate I (Fig. i). He made a very large number of experi- 
ments and found numerical agreement between the results of 
his experiments and de Broghe’s formula within the limit 
of experimental errors ; actually the agreement was within 
a very few per cent. From this he drew the conclusion 
that the electron is accompanied by trains of waves, whose 
wave-length is inversely proportional to the velocity, and 
that these waves guide die electrons. That the various 


rings of the photographic plate are due to electrons and 
not to waves travelling independently, is shown by the 
fact that if after passing through the film, and before 
reaching the photographic plate, the electron is deflected 
by a magnet, the whole system — central spot and rings — 
is deflected, and the relative intensity of the various parts 

As the result of his experiments, Thomson came to the 
conclusion that each electron is associated with a wave 
whose wave-length is approximately h/mv, the length of 
the train being at least 50 wave-lengths and the breadth of 
the wave front at least 30 x io“® cm. When the electron is 
moving with uniform velocity and is in a steady state, if 
there is any energy in the train of waves it must travel 
with the velocity of the electron, which is small compared 
with that of light. 

The explanation of “ beats ” in sound waves shows that 
there may be two velocities associated with waves. Sup- 
pose that a disturbance represented by a cos {pt - mx) is 
superposed on another represented by a cos {p^t ~ m'x), 
the resultant is a cos {pt - mx) -\-a cos {p't - mx) 

=2 a cos |{(p -p)t - (w - m')x) 

cos ^{{p-\-p')t~ (m+m')x) 

or if p and p are nearly equal 

2 a cos \{{p -p')t - (m - m')x) cos {pt ~ mx). 

This can be regarded as a vibration cos {pt - mx), whose 
amplitude varies as a cos i{{p -p')t- {m -m')x). This 
represents a wave whose velocity is {p - p')l{m -m') or 
in the hmit dpjdm. Now the energy in the wave at any 
place depends upon its amplitude, so that dpjdm represents 
the velocity of propagation of the energy, while pjm re- 
presents the velocity of the phases of the wave cos {pt - mx ) . 


The quantity measured in experiments on electron waves is 
the wave-length of the waves represented by cos (p^ - mx) : 
why is this connected with the velocity of the electron ? 
It is because in certain important cases, e.g. that of the 
propagation of waves through a medium which has an 
intrinsic frequency of its own, the product of the phase 
velocity and the energy velocity is equal to the square of 
the velocity of light. If is this intrinsic frequency the 
equation of wave motion through the medium is 

or if 4 >=cos (pt - mx) 


The phase velocity is pjm, the energy velocity dp/dm^ 
the product of the two is or ; this by the preceding 
equation is equal to c^. From this equation too we get 

Am 2'7rc^ 

— = = constant. 


Here A is the wave-length of the phase velocity = 27 r/m, and 
M the energy velocity which is that of the electron. If we 
suppose that 27rc^ jp ^ = where is the mass of an electron 

at rest, and h Planck’s constant, this is exactly the same as 
de Broglie’s equation, with which Professor Thomson’s 
results were in excellent agreement. But though there is 
formal agreement between the theoretical expression and 
the experiments, the numerical results give rise to difi- 
culties. From the sharpness of the rings Professor Thomson 
concluded that there must be at least 50 wave-lengths in a 


train of waves, and that the wave-lengths were comparable 
with I0“® cm. Thus the dimensions of the train would be 
enormous compared with the usual estimate, 10“^^ 
the diameter of an electron. This is not quite conclusive, 
however, for the wave-length of visible light emitted by 
a luminous atom is also enormously greater than the linear 
dimensions of the atom, and the quantum of light must be 
a train of a large number of wave-lengths to explain the 
optical effects ; this long train must have been manufactured 
within the short atom and then expelled, and it is possible 
that the long train of electronic waves may have started at 
a distance from the electron very much less than the wave- 
length of the electronic waves. 

Positive Rays 

The cathode rays start from the cathode and move away 
from it. Goldstein, who devoted a long Hfe to the study 
of the electric discharge through gases, and who made 
many discoveries of first-rate importance, found in 1886 
that there were rays moving towards the cathode and 
striking against it. Using a cathode perforated by small 
holes he observed luminous pencils streaming through 
the holes. These he called ** Kanalstrahlen ” ; the colour 
of these pencils was not the same, however, as that of the 
cathode rays. A more fundamental difference was that 
these rays were not appreciably deflected by magnetic 
forces which produced large deflections of cathode rays ; 
indeed it was not until sixteen years after their discovery 
that their deflection by a magnet was observed by Wien, 
who found that it was in the opposite direction to that of 
cathode rays, so that these rays carried positive charges. 


He obtained, too, direct evidence of these charges, and by 
measuring the deflection under electric and magnetic forces, 
he obtained lo^ as the maximum value of ejm; this is the 
value for the hydrogen atom in electrolysis. I thought the 
study of these rays might throw hght on the nature of the 
carriers of positive electricity. Are they, for example, all of 
one type, like the carriers of negative charges ? The method 
I used for this purpose was to send a narrow pencil of rays 
through the space between two parallel brass plates and 
apply in the space between these plates electric and mag- 
netic forces, both at right angles to the plates. If the plane 
of the paper is at right angles to the beam of electrified 
particles, and also to the plates, and if AB and CD are 
the lines of intersection of this plane and the plates, then, 
as the beam passes between the plates, the electrified par- 
ticles will be acted upon by two forces at right angles to 
each other ; a horizontal one due to the electric field and 
a vertical one due to the magnetic. The rays when they 

strike against a photographic plate produce a spot where 
they hit the plate. Suppose this plate is placed at right 
angles to the beam of rays, and that when neither electric 
nor magnetic forces are acting, the rays hit the photo- 
graphic plate at O, and that when the electric and magnetic 
forces are on, O is displaced to P. 



Then if Ox and Oy are respectively horizontal and vertical 
lines through O, and PN is vertical, ON is the displace- 
ment due to the electric force and PN that due to the 
magnetic force. 

It can be shown that 


where e is the charge, m the mass and the velocity of 
the particle, H the magnetic and X the electric force, and 
A a quantity depending only on the geometry of the system, 
t\e. on the length of the path of the particle between the 
plates AB and CD and on the distance from them of the 
photographic plate. Writing y for PN and for ON we see 

x= — -A (i) 

1 He, 

and y= — A | 

HiJ . . 


and y^=- — 

^ m X 


From equation (3) y/x does not depend on the mass but 
only on the velocity; all the points in the photograph lying 
on a straight line passing through O will correspond to 
particles having the same velocity. Since equation (4) 
does not involve the velocity but only the mass, all the 
points on the parabola represented by this equation will 
correspond to particles having the same mass. If there 
are particles of different mass in the beam of rays there will 
be a different parabola for each type of particle. 

It follows from equation (i) that if T be the kinetic 
energy of an electrified particle, x=XeA/2T, The energy 
of the particles is due to the forces acting upon them before 
they passed through the cathode ; these, if the charges on 


the particles are equal, will be the same for particles of 
aU kinds ; in particular the maximum energy which the 
different particles acquire will be the same, and therefore 
the minimum value of jc:. Thus the parabolas will all 
stop at the same distance from the vertical. If some 
particles had a double charge of electricity when in the 
discharge-tube, and lost the extra charge before passing 
through the parallel plates, they would have acquired twice 
the normal amount of energy, so that their parabolas 
would reach to half the normal distance from the vertical. 

On trying this method I met at first with great diffi- 
culties. This was due to the fact that these positively 
charged particles have very httle penetrating power com- 
pared with the cathode rays, so that unless the pressure 
is very low they will not reach the photographic plate. 
We are then met with the difficulty that the discharge 
required to produce these rays will not pass when the 
pressure is low enough to enable the positive rays to reach 
the plate, and if the pressure in the discharge-tube is higher 
than on the other side of the cathode, gas will flow through 
the holes and raise the pressure on that side. To stop 
this as much as possible a long straight tube of fine bore, 
like a hypodermic needle, was fixed in the hole so that 
the gas had to pass through this tube, which offered a 
considerable resistance and made the rate of leak slow, but 
still large enough to require continual pumping to enable 
the rays to reach the plate. At first all we got on the plate 
was a straight line passing through the origin. The value 
of ejm for the tip of this line was io+, and we got this line 
and no other whether the gas introduced into the discharge- 
tube was air or nitrogen or CO^, and it looked as if the 
carriers of the positive electricity were all of the same kind 
and were atoms of hydrogen. However, by using very 

353 2A 


large vessels for the discharge-tube, which allowed the dis- 
charge to pass at a lower pressure than the smaller ones 
we had previously used, we got two lines on the plate and 
the value of ejm for the tip of the second line was iio^, 
the value for a molecule of hydrogen. These two hydro- 
gen lines were the only ones we got until we put some 
hehum in the tube, when a third line with e/m, Jio+, the 
value corresponding to an atom of helium, appeared. 
This was very important, for it was the first evidence we 
got that the positive particles could be other than hydro- 
gen atoms or molecules. At this stage, through the 
generosity of Mr T. C. Fitzpatrick, a plant for making 
liquid air was installed in the laboratory, and we were able 
to use Dewar’s method of producing a vacuum by absorb- 
ing the gas by charcoal cooled with liquid air. Now the 
worst of our troubles were over, we had no difficulty in 
getting parabolas corresponding to the atoms and mole- 
cules of the different gases in the discharge-tube — nitrogen, 
oxygen, carbon. The reason we had only got hydrogen 
to begin with is that there is always hydrogen condensed 
on the glass walls of the discharge-tube which is given off 
when the discharge passes through it. These light atoms 
and molecules have much greater powers of penetration 
and can reach the plate when the atoms and molecules of 
the heavier gases are unable to do so. Helium, the next 
hghtest gas, has also great penetrating power, and it was 
able to reach the plate almost as well as hydrogen. These 
experiments show that the positive charges, unlike the 
negative ones, can be carried by the atoms and molecules 
of all gases, elements or compomids, and suggest that a 
positively charged particle is just one that has lost an 
electron. The difference made by the improvement in the 
vacuum is illustrated in Plate I (Fig. 2) , taken after we used 


liquid air. The gas in the tube was that left in after the 
gas had been pumped out until the pressure was very low. 
There are parabolas due to particles for which {mje) 
equals i, 2, 12, 14, 16, 28, 44, due to atoms and molecules 
of hydrogen, atoms of carbon, nitrogen and oxygen, mole- 
cules of nitrogen, carbon monoxide and carbon dioxide 
respectively. Some of these are due to gases coming from 
the walls of the tube. Each kind of charged carrier pro- 
duces its own parabola on the plate ; there are as many 
parabolas as there are different kinds of carriers. We get 
a spectrum of the gas and from an inspection of the plate 
we can determine not only the number of kinds of carriers, 
but also from the dimensions of the parabolas the atomic 
or molecular weight of each carrier. This type of spec- 
trum enables us to determine the nature of the gases 
inside the tube and thus provides a method of chemical 

The positive ray spectrum has for this purpose many 
advantages over ordinary spectrum analysis. If a spectro- 
scopist observes a line unknown to him in the spectrum 
of a discharge-tube, the most he can infer, without further 
examination, is that there is some unknown substance in 
the tube, and even this might be doubtful, as the new line 
might be due to some alterations in the conditions of the 
discharge. But if we observe a new parabola in the positive 
ray spectrum all we have to do is to measure the parabola, 
and this at once tells us what is the atomic weight of the 
particle which produced it. By giving long exposures 
we can make the method exceedingly dehcate, and detect 
the presence of a trace of gas too small to be detected by 
spectroscopy. The amount of gas required is very small, 
as the pressure of the gas is exceedingly low, generally less 
than one-hundredth part of a millimetre of mercury. 



Another very important advantage is that this method is 
not dependent upon the purity of the gas ; impurities 
merely appear as additional parabolas in the spectrum and 
do not produce any error in the determination of the atomic 
weight. The rays are registered on the photograph within 
much less than a millionth of a second after their forma- 
tion, so that when chemical combination or decomposition 
is going on in the gases in the tube, the method may dis- 
close the existence of intermediate forms which have only 
a transient existence, as well as that of the fmal product, 
and may thus enable us to get a clearer insight into the 
process of chemical combination. 

I took a great many photographs of the parabolas 
when different gases were put in the discharge-tube. 
Among these were some samples of gases obtained from 
the residues of liquid air. This gave, along with other 
parabolas, a strong parabola of neon, atomic weight 20 ; 
and the neon parabola was always accompanied by one 
close to it, corresponding to a particle of atomic weight 
22, and by another much fainter one, corresponding to a 
particle for which ejm was ii, the value it would have if 
the atom of the line 22 had a double charge of electricity. 
The atoms of nearly all the elements except hydrogen can 
carry a double charge, while it is very exceptional for 
a molecule to do so. This was against the line 22 being 
due to a hydride NeHa. The same objection would 
apply to its being a molecule of CO^ wnth a double charge, 
which would give the parabola with m/e =22, and in 
addition to this difficulty there is the fact that all the CO2 
can be removed from the gas without affecting the strength 
of the line. Whenever neon was present the line was 
there, and it never occurred except accompanied by the 
neon line. It was the first example of an Isotope. Two 


elements A and B are isotopes if their chemical properties 
are identical but their atomic weights different. 

Professor Soddy shortly before the discovery of the 
isotope of neon had suggested the possibiHty of the exist- 
ence of such things as isotopes. Since the chemical pro- 
perties of an atom depend on the arrangement of the 
electrons near its surface, they are only skin deep. If from 
the centre of the atom a proton with a positive charge and 
an electron with a negative one were removed simultane- 
ously, the electric field at the surface of the atom would not 
be changed and therefore the arrangement of the electrons 
at the surface not affected, so that the chemical properties 
would be unaltered while its atomic weight would be 
diminished by unity. Neither chemical nor spectroscopic 
tests could distinguish between them, while physical ones 
such as trying to separate them by diffusion have not been 
successful, so the positive ray test is the only one available. 

Aston, who has made very extensive and valuable 
experiments on isotopes and has discovered isotopes for 
most of the elements, did not use the parabohc method, 
but one where rays of different velocity but of the same 
mass were brought to a focus and the effect on the photo- 
graphic plate thereby increased. The electric and magnetic 
fields were placed in series, instead of being superposed as 
in the parabola method, and the magnetic force was at 
right angles and not parallel to the electric. This arrange- 
ment makes the force exerted by the magnetic field on 
the charged particles parallel to, but in the opposite direc- 
tion to, that exerted by the electric. It focusses the rays 
of different velocity on the same principle as two prisms, 
made of different kinds of glass and arranged so as to bend 
rays of light in opposite directions, can bring rays of light 
of different colours to the same focus. The two prisms 



in the optical experiment are analogous to the electric 
and magnetic fields which bend the positive rays in opposite 
directions in the electric one. The variation of the amount 
of bending with the wave-length in the optical experiment 
is analogous to the variation of the bending with the 
velocity of the rays in the electric one. And, just as we 
cannot obtain achromatism by using two prisms of the 
same kind of glass, so we cannot focus the positive rays 
by using two electric or tw’o magnetic fields while we can 
when one field is electric and the other magnetic. The 
reason of this is that the change of the deflection with the 
velocity, which corresponds to the dispersion of light in 
the optical problem, varies inversely as the square of the 
velocity in the electric field, and only inversely as the 
velocity itself in the magnetic. There is thus a difference 
in the law of dispersion in the two fields, just as there is in 
prisms made of different kinds of glass in the optical one. 

Under good conditions the parabola method need not 
be inferior in sensitiveness to the focus method. Indeed, 
quite lately, Zeeman, using the parabolas, detected an 
isotope of argon which had escaped notice by the focus 
method. The parabola method has for many purposes 
considerable advantage over the other. It shows the whole 
spectrum at a glance : the parabolas have a structure of 
their own ; sometimes there are concentrations in particu- 
lar spots ; sometimes besides the parabolas there are straight 
lines on the plates. The beam of rays sometimes contains 
negatively electrified particles as well as the positive ones ; 
these give rise to another set of parabolas. All these 
pecuharities, which throw much light on the processes 
taking place in the discharge-tube, are much more easily 
detected and investigated by the parabola method than 
by the other. 



When the pressure is not too low to allow of collisions 
between the molecules of the gas in the tube with the 
charged particles on their way to the photographic plate 
there are, in addition to the parabolas, lines starting from 
the position of the undeflected spot. These lines are gener- 
ally straight; they reach in some cases to one of the 
parabolas and then stop. In other cases they stop before 
reaching a parabola. The first kind of 
lines are due to particles some of which 
have lost their charges while going 
through the electric and magnetic fields 
and so have not experienced the full 
deflection. The lines which stop before 
they reach a parabola are due to par- 
ticles which have lost their charge 
before passing out of the fields. Again, 
the parabolas themselves show differ- 
ences which give important informa- 
tion. The majority of the parabolas 
start from points in the same vertical line if the magnetic 
deflection is in this direction. The horizontal distance 
from the line of no electrostatic deflection is inversely 
proportional to the energy of the charged particle, so that 
if the parabolas all start at the same distance from this line, 
the maximum energy possessed by the particles is the same 
for all. This we might expect as the charges carried by 
them are the same, and the maximum potential difference 
through which they fall, that between the electrodes in 
the tube in which they are produced, is the same. There 
are, however, some parabolas whose tips are nearer the 
vertical line than the others, showing that their particles 
possess an abnormal amount of energy; a case of this kind 
is shown in Plate I (Fig. 3), where the distance of the tip of 


one of the parabolas is only half that of the others, showing 
that the maximum energy of this kind of particle is twice 
the normal. This is what would happen if some of the 
particles lost two of their electrons instead of one before 
passing through the cathode; they w'ould have a double 
charge, and so receive in the discharge-tube twice the 
normal energy, while if they regained an electron after 
passing the cathode and before reaching the electric and 
magnetic fields, they would lie along the parabola corre- 
sponding to the normal charge ; those which did not lose 
their second charge would appear along the parabola with 
a double value of e/m, and this second parabola can always 
be found along with the one showing the prolongation. 

The discharge decomposes the gas through which it 
passes, splitting up the molecules of the elementary gases 
into atoms, and the molecules of compoimds into any com- 
bination which can be made of the elements of which they 
are composed. The discharge is accompanied by association 
as well as decomposition : thus when marsh gas was in 
the tube, Conrad ^ got the positive ray spectrum shown in 
Plate I (Fig. 4). There are in this spectrum lines corre- 
sponding to 

C,H„ CH„ CH„ CH3, CH^ 

C„ C,H, C,H3, 

C3, H3, C3H, C3H,, C3H3, C4H4 

It seems that every possible combination of the atoms of 
the gas through which the gas passes are produced without 
any limitation by considerations of valency. It must be 
remembered that these combinations are recorded in a 
fraction of a mUHonth of a second after they are produced, 
and so may have only a very short hfe. 

I Phys. Zeits. 31, p. 888, 1930. 



Negatively charged Atoms 

In the photographs of the parabolas of the positive rays 
we often find parabolas where both the electric and mag- 
netic deflection of the particles are in the opposite direction 
to those of the normal parabolas. This shows that these 
parabolas are formed by particles which carry a negative 
charge. Before they passed through the cathode they were 
positively charged, and they owe their velocity to the action 
on them, when in this condition, of the electric force in the 
discharge-tube. After passing through the cathode they 
attract first one electron which neutrahses them, and then 
another which gives them a negative charge. These 
negatively charged particles are, in comparison with the 
positively charged ones, more conspicuous at high press- 
hires than at low. The negatively charged hydrogen atom 
can generally be detected down to fairly low pressure. 
At these pressures the negatively electrified molecule can- 
not be detected, while at higher pressures it is immistakable. 
At still higher pressures I have seen the parabola due to 
negatively charged hydrogen atoms as bright as that due 
to the positive ones. 

The electrochemical properties of the gases have a more 
conspicuous influence on the occurrence of these negative 
rays than on any other phenomenon connected with posi- 
tive rays. For example, the atoms of the electronegative 
elements oxygen and chlorine are remarkable for the ease 
with which they acquire a negative charge. Carbon and 
hydrogen do so too, though they are not regarded as 
electronegative elements ; I have never seen the negative 
parabolas for the inert gases, hehum, nitrogen, neon, 
argon, krypton, xenon, nor that of mercury, though the 


positive ones were very strong. Another effect which 
is very useful in interpreting positive ray photographs is 
that negatively electrified molecules, with the exception 
of those of hydrogen, oxygen, carbon, and these but 
rarely, are not found among the positive rays. Some 
radicles such as OH, CH2, CH, occur with a negative 
charge when hydrocarbons are in the tube. 

The prolongations of the parabola test whether a para- 
bola is due to an atom or a molecule. All atoms except 
those of hydrogen seem under certain conditions to 
give prolonged parabolas while molecules very seldom 
do so. The parabolas due to the atoms of mercury have 
abnormally long prolongations — the one corresponding to 
the singly charged atom is prolonged until its tip is only 
one-fifth of the normal distance from the vertical, showing 
that some of the atoms have lost 5 electrons; there are 
parabolas corresponding to atoms with 2, 3, 4, 5 charges 
respectively. I have also detected atoms of nitrogen and 
oxygen with 3 charges. 

Electric Method 

The photographic method, how^ever, is not metrical : 
the intensity of the parabolas for different elements is 
not proportional to the number of particles producing 
them. The atoms of the Hght elements produce a much 
greater photographic effect than those of the heavier ones. 
Thus the parabolas for H"*" and Hj'*' may be by far the 
strongest on the plate, when the amount of hydrogen in 
the tube is but a small fraction of that of other gases. 

A method which is much more metrical is to use instead 
of the photographic plate a metal plate in which a para- 


bolic slit is cut ; behind the slit is a Faraday cylinder con- 
nected with an electrometer; the positively charged par- 
ticles passing through the slit charge up the electrometer 
and the deflection of the electrometer measures the charge 
received in a given time. It is not necessary to have more 
than one slit even when there would be many parabolas 
on a photographic plate, for one parabola after another can 
be driven on to the slit by altering the magnetic field used 
to deflect the particles. The method is very definite ; a 
change of a few per cent in the magnetic force is enough 
to make the difference between no deflection of the electro- 
meter and a very large one. When the particles lose their 
charges before reaching the plate the two methods do not 
measure the same thing ; the photographic method records 
all particles, whether charged or uncharged, which reach 
the plate, the electrometer method only those which are 
charged. Information about the stability of different kinds 
of charged particles can be got by applying both methods 
to the same gas. Thus at certain pressures the strength of 
the photograph of the parabola due to the negatively 
charged hydrogen atom is comparable with that of the 
positively charged one, but while the positive one gives a 
large deflection with the electrometer method, the negative 
one does not give one large enough to be measured, show- 
ing that the negative one does not retain its charge even 
for the short time, less than i/iooooo of a second, required 
to pass from the place where it was formed to the electro- 

Again, one of the first things discovered by the photo- 
graphic method was the existence of Under suitable 

conditions its parabola may be of very considerable strength, 
stronger than many of the other parabolas, while when 
tested by the electrometer its effect is only a very minute 


fraction of that due to the lines it excelled before, showing 
that the greater number of the particles lose their positive 
charge, i.e. become neutral, in a minute fraction of a 
millionth of a second. The other form of hydrogen with 
the same molecular weight DH, when D is the atom of 
the isotope of hydrogen, whose mass is 2, gives an effect 
on the electrometer of the same order as that on the 
photographic plate, behaving in this as in other respects 
like H2. Though is so evanescent, H3 itself is much 
more durable, for when H3 has once been observed in a 
tube, then, though the tube has not been sparked for several 
days, Hjwill at on ce appear when sparking is resumed though 
it gets fainter as time goes on. Presumably it adheres to 
the glass wall of the tube and is, like layers of H and CO, 
not easily detached. 

Mass^ Momentum and Energy of Moving Charges 

On Maxwell’s theory the velocity of light is equal to 
a well-known electrical constant whose value had been 
determined before the theory had been proposed. Other 
theories, for example the elastic solid theory, give ex- 
pressions for it in terms of quantities we know nothing 
about, but his is the only one which says that the velocity 
must be 3 X io*° cm./sec. 

It may at first sight seem surprising that a velocity 
which appears in such a prosaic form as the ratio of two 
electrical units should be of such outstanding importance 
in modern physics, but we must remember that on modem 
views matter is supposed to have an electrical structure, 
and that on Maxwell’s theory light is an electrical pheno- 



Maxwell only applied his theory to a medium devoid 
of electric charges, hut if we apply it to the case of a 
moving electric charge we arrive at conclusions of a very 
fundamental character, similar to some of those which were 
at a later date arrived at from considerations of relativity. 

Let us take a very simple case to begin with, that of a 
charged sphere moving in a straight line with a velocity 
very small compared with that of hght. Since the charge 
is moving, the electric force at a point in its neighbour- 
hood will change, and on Max- 
well’s theory changes in elec- 
tric forces produce magnetic 
forces, hence there must be 
magnetic force in the space 
around the moving sphere. Maxwell’s theory appHed 
to this case shows that the moving charge will produce 
at a point P a magnetic force equal to eu sin djr^, where 
e is the charge measured in electromagnetic unit, u the 
velocity of the charge, OX the direction in which it is 
moving, and 0 the angle POX, O the centre of the charge 
and r==OP. The direction of the force is at right angles 
to the plane POX, i.e. the plane which contains the radius 
vector OP and the direction of motion OX. But wher- 
ever there is magnetic force there is energy. The energy 
per unit volume at a place where the magnetic force is H 
is In the case of the moving particle, sin djr^, 

so that at P the energy per unit volume is sin^ ; 

integrating this over the region outside the, surface of the 
sphere, we find that the energy outside the sphere is 
2e^u^l'^a^ where a is the radius of the sphere. 

If M is the mass of the sphere when it is without a 
charge, the kinetic energy of the charged sphere will be 
{M+4e^l'ia)u^/2. Thus the effect of the charge has been 


to increase the mass by 4e^l3a; now eH^l2a, c being the 
velocity of light, is the energy in the space outside the 
charged sphere, so that the charge on the sphere has in- 
creased its mass by 8/3 times the increase in the energy. 
The increase in mass is thus proportional to the energy of 
the electrified system. Though the charge of electricity 
may be the same, the increase in the mass will be greater 
when it is spread over a small sphere than over a large one. 
The increased mass is distributed throughout the region 
surrounding the charged body. We may compare this 
increase in mass with that which occurs when a sphere is 
moving through water. If M is the mass of the sphere, 
its effective mass when moving through water is not M 
but M+m/2, where m is the mass of an equal volume of 
water. The reason for the increase in mass in this case is 
obvious. The sphere cannot move without setting the 
surrounding water in motion, so that when it moves the 
mass in motion is not only the mass of the sphere, but also 
the mass of the water set in motion by the sphere. 

The increase in mass is the same for positively as for 
negatively electrified particles if they are of the same size, 
and we can prove without difficulty that if a number of 
charged particles are separated by distances large compared 
with their diameters, as they are in an atom regarded as a 
collection of protons and electrons, the energy of the atom 
will be the sum of the energies of the individual protons 
and electrons of which it is composed. It has just been 
shown that the mass of each constituent is in a constant 
proportion, 8/3 to its energy. Therefore the sum of 
the masses of the constituents will bear the same propor- 
tion to the sum of their energies. Hence the mass of the 
atom will bear a constant proportion to its energy. An 
uncharged body may be regarded as one containing as 


many protons as electrons. The proportion between mass 
and energy would be again the same. Thus the energy 
of any body is equal to the product of its mass and a mul- 
tiple of ; this result was arrived at before it was deduced 
from the principle of relativity. 

We can, however, go further than this. We have 
supposed that the velocity of the particle was so small 
compared with that of hght that the squares of the ratio 
of the two may be neglected. We can, however, get from 
Maxwell’s theory the solution without this Hmitation. It 
follows from the theory that when an electrical charge 
is moving, the distribution of electrical force round the 
particle is not the same as when the particle is at rest. In 
the latter case the force is symmetric dly distributed round 
the particle. If O is the centre of the particle, the force 
at P is e/OP^ whatever may be the direction of OP, but 
when the particle is moving in the direction OX, the force 
depends on the angle between OP and OX. It has been 
shown by Lorentz and Heaviside that if x, y, are the 
co-ordinates of a point on a line of electric force when the 
charge is at rest, xS yS the co-ordinates of the same point 
when it is moving with velocity u, then if u^jc^) 

x^=kx, y^=y, z^=z. 

These equations show that the system of lines of force 
connected with the charge suffers a uniform contraction 
in the direction of x, i.e. in the direction in which the charge 
is moving, and thus the lines offeree tend to set themselves 
at right angles to the direction in which they are moving. 
When the particle is moving with the velocity of hght 
u=c, and fe=o, so that x^=o, i.e, all the lines of force are 
at right angles to the direction of motion of the charge. 
If we regard the charged body as merely the terminus of 


the lines of force, as would for example be the case if the 
charge were a hole in the ether on which lines of force ter- 
minate, then, if when at rest they terminated on a sphere 
of radius a, represented by the equation 
they would when in motion terminate on the ellipsoid 

This is called the Heaviside Ellipsoid. The shape of the 
charged body would be changed by its motion. 

The Mass of the Moving Charge 

The momentum per unit volume at any point (x, y, z) 
in the electric field is equal to the vector product of the 
electric and magnetic forces. From this it follows that 
the momentum parallel to x is per unit volume 



and integrating this throughout the region outside the 
Heaviside Ellipsoid whose boundary is Xj^jh +yj^ 

2 e^u 

we fmd that the momentum = 

3 ak 

Since the momentum is the product of the mass and 
the velocity, the mass of this moving charge is 

2 e ^_2 

3 3 aV{i-u^l^y 

a result which was first obtained in a different way by 
H. A. Lorentz. Thus the mass of the moving electron 


varies as i/Vi ” u^je^ and therefore increases as the velocity 
increases, and at the same rate as that which subsequently 
was indicated by the principles of relativity. 

On this view the mass, momentum and energy of the 
charged sphere are distributed throughout the medium 
around it, and are not in the sphere itself. We shall call 
this medium, in which Maxwell’s equations are assumed 
to hold, the ether, and if we assume the electrical theory 
of matter, i,e. that it is composed of electrons and protons, 
it follows that all mass, momentum and energy are in the 
medium surrounding the matter and not in the matter 
itself. If this is so, there must be some connecting link 
which binds a charged body to a portion of the ether, 
thereby endowing the body with mass, momentum and 
energy. These links I regard as suppHed by the lines of 
force proceeding from charged bodies. We may use a 
hydro dynamical analogy to make this clearer, and com- 
pare lines of electric force with vortex filaments. When 
a long straight vortex filament moves through a Hquid, 
the lines of flow of the Hquid outside the filament are of 
two classes ; there is a region extending to some way from 
the filament where the lines of flow are closed curves ; the 
fluid in this region just moves round and round the fila- 
ment and is carried along with it, and its mass may be 
regarded as the mass of the filament. Outside this region 
the lines of flow are not closed curves and the Hquid does 
not accompany the filament. The volume of Hquid 
moving with the filament depends on the “ strength ” of 
the filament and not on its volume, which may be quite 
insignificant in comparison with that of the Hquid which 
it carries along with it. Again, the volume it carries with 
it is proportional to the square of the strength of the 
filament, so that two filaments close together will carry 


along with them twice as much liquid as if they were a con- 
siderable distance apart. We have seen that the effect of an 
increase in velocity of a charged body is to crowd the lines 
of electric force closer together and tliis, on the analogy 
between lines of electric force and vortex filaments, would 
produce an increase in its mass. On this view the ether 
outside the charged body is the seat of all mass, momentum 
and energy, and the dynamics of the electric field is the 
dynamics of this system and for this the mass, momentum 
and energy will remain constant, i.e. the Newtonian 
mechanics will apply. Part of this system is not connected 
up with matter ; the Newtonian mechanics apphes to the 
whole system, but not necessarily to a limited portion of it 
which can receive from or give up mass, momentum and 
energy to the other. 

Let us take a very simple case to illustrate this point, 
one where the electric force is due to a charge of electricity 
at A and a magnetic pole of strength m at B. When there 
are both electric and magnetic forces at a point P there is 
momentum, and the momentum per unit volume is equal 
to the vector product of the electric and magnetic forces 
at P. From this we find by integration that the system 
has a moment of momentum about the line AB equal to 
em. Now suppose A and B are moving ; if the motion 
is such that there is no velocity of A relative to B the 
direction of AB will not change and there will be no change 
in the moment of momentum in the ether. But suppose 
A is moving relatively to B ; take the case when the relative 
velocity of B and A is at right angles to AB and equal to 
V, then in the time (supposed small) AB will turn through 
an angle vt^JAB; the axis of the moment of momentum 
is turned through this angle, and the difference between 
the old value and the new is equal to a moment of mo- 


mentum {emlKB)vt^ whose axis is at right angles to AB 
and in the plane of the paper. There is thus a change in the 
moment of momentum of the medium. Next consider 
the moving charges : the moving charge e will exert on the 
magnet pole m a force emvlAB^ at right angles to the plane 
of the paper, and the moving pole B will exert on the 
charge e a force of the same magnitude, but in the opposite 
direction ; as the forces are equal and opposite there is no 
change in the momentum, but as they are not in the same 
straight line they will produce a couple whose moment is 
emt'/AB, and whose axis is in the plane of the paper at right 
angles to AB. In the time this will produce a change in 
the moment of momentum of the pole and charge equal 
to (emlA3)t^ which is the same in magnitude, but in the 
opposite direction to that produced in the ether, so that 
there is no change in that of the complete system. 



Physics in my Time 

W HEN I began research in physics in the early 
seventies, the subject which was exciting most 
interest was the “ Light Mill ”, or radiometer, 
invented by Sir William Crookes. This, in its commonest 
form, was four thin mica discs fastened to the ends of a 
horizontal cross which could spin round on a pivot sup- 
ported in a glass cup. These were enclosed in a glass 
vessel which contained air at a very low pressure. The 
vanes were blackened with lamp-black on one side but 
were bright on the other, and when exposed to light they 
rotated round the pivot, the direction of rotation being 
the same as if the blackened side were repelled by the Hght. 
These light mills aroused the interest of the general pubHc, 
and shopkeepers had them rotating in their windows to 
attract a crowd. The discovery of the radiometer by 
Crookes was a triumph of vigilance in observation and 
accurate measurement. When he was making very accu- 
rate weighings to determine the atomic weight of thalhum, 
an element he had lately discovered, he found small dis- 
crepancies which he could not account for by any known 
source of error. He set himself to discover the origin of 
these, and by ingenious experiments convinced himself that 
they were due to the light falling on the balance. This led 
him to make ad hoc experiments on the effect of Hght on 
delicately poised pieces of metal, and hence to the dis- 
covery of the radiometer. At first the rotation was 


ascribed to the pressure of the light itself. Maxwell had 
shown that, on his electromagnetic theory of light, Hght 
ought to exert a pressure on surfaces on which it falls, 
and this pressure was detected in 1901, nearly twenty years 
after the discovery of the radiometer, by the Russian 
physicist Lebedew. This pressure is, however, far too 
small to account for rotations as great as those observed 
in the radiometer, and the rotation would be in the opposite 
direction. For suppose a Hght particle, a photon, fell on 
the blackened surface of a vane of the radiometer, it would 
be absorbed and would give up its momentum to the vane. 
If it were to fall on the bright surface, it would be reflected 
and would possess a momentum, equal in magnitude to that 
it possessed before striking the vane, but in the opposite 
direction, the reflecting vane would recoil with a momen- 
tum equal and opposite to that given to the reflected 
photon ; thus the reflection from the vane would double 
the momentum it would receive if the photon were merely 
absorbed. Thus the bright surface would be repelled by 
the Hght more than the blackened one, while in the radio- 
meter the repulsion is less. Another very ingenious test 
was suggested by Osborne Reynolds, and carried out by 
Schuster. If the rotation were due to the pressure of the 
Hght on the vanes, it would not set up any rotation in the 
glass vessel in which the vanes were contained, but if it 
were due to effects inside the radiometer, then, by the 
principle that action and reaction are equal and opposite, 
if the vanes rotated in one direction the glass case must 
rotate in the opposite. The experiment was made in the 
laboratory of the Owens College ; the radiometer was 
suspended by a fine thread so that it could rotate freely if 
it wanted to. I can still remember the excitement and 
anxiety with which I waited for the verdict, and the reHef 



on hearing that the case had rotated in the opposite direc- 
tion to the vanes. The cause of the rotation of the vanes 
is that the blackened surfaces get hotter than the bright 
ones owing to their absorbing more light. When the 
molecules of the gas strike the blackened side they get 
hotter, and shoot off with a higher velocity than after 
striking the colder bright one, thus the kick or recoil is 
greater on the blackened surface than on the bright. His 
experiments on the radiometer led Crookes to study other 
phenomena in gases at very low pressures. In his time 
the production of a good vacuum was lengthy, tedious and 
arduous. The only means available were Sprengel or 
Topler pumps ; both these required the continual raising 
and lowering of a vessel full of mercury, and it often needed 
a morning^s pumping to get a vacuum good enough for the 
most important experiments. With the pumps now avail- 
able a much better vacuum can be got in a few seconds. 
The introduction of electric light made the production of 
vacua a matter of commercial importance, as the air had to 
be pumped out of the lamps. This set inventors at work 
to produce a pump which should be automatic and rapid. 
The first satisfactory automatic pump was invented by 
Gaede in 1905, and from that time there has been a steady 
stream of automatic pumps working on a great variety of 
principles. Gaede himself has invented at least three 
different types of pumps, while successful pumps have been 
introduced by Langmuir, Waran and others. Some of 
these, it is claimed, can deliver five or more litres per second, 
and can reach a vacuum where the pressure is only one- 
thousand-millionth part of atmospheric pressure. This 
means that, of the molecules present in the vessel before 
the pumping began, only one in a thousand mdlions is left 
after it has been completed. And what is even more im- 


portant for the investigation of the properties of matter is 
that the odds against one molecule coming into collision 
with another when it passes over a length of one metre 
is about 70 to 1, Thus, even in very large vessels, a mole- 
cule behaves as if no other molecules were present. At 
these pressures we can study the properties of individual 
molecules when they can do as they wish, whereas at 
considerably higher pressures wc can only study their 
behaviour in a dense crowd when they have to do what the 
crowd dictates. The improvement in recent years in tlic 
production of high vacua is an example of the advantages 
which accrue to the study of any branch of science when 
it has industrial applications ; then tlic improvement of any 
technique becomes of commercial importance on which 
large sums may be profitably spent. The manufacture of 
vacua is an important industry. Kaye in his book High 
Vacua quotes Dr. Whitney as saying, when he was 
President of the General Electric Company of America, 
that the American public alone purchases “ over a million 
dollars’ worth of glass vacua yearly This was ten years 

ago, and in the interval the demand for vacua for electric 
lighting and wireless has much increased all over the world. 
I should think it would be an underestimate to put the 
trade in vacua, taking all countries into account, as 
1 00,000,000 sterling a year. 

The improvement in the pumps since 1905 has been in 
the speed with which they work. The method of produc- 
ing vacua (absorbing the gas by charcoal cooled by liquid 
air) introduced by Dewar at the beginning of this century 
produced as good, and in some respects better, vacua than 
any method since introduced ; the only objection is that 
it is much slower. Owing to Dewar’s discovery, physicists 
since the beginning of this century have been in possession 



of a means of studying matter in so rarefied a state that each 
particle acts independently of its neighbours. This has 
been of supreme importance to the progress of science. 
Crookes’ experiments on the passage of electricity through 
gases were made before Dewar vacua had been invented, 
but by improving the Sprengel pump he was able to get 
down to pressures of about of a millimetre, when 
the free path would be comparable with 7 cm., which 
would be low enough to give a molecule a fair chance of 
getting across the tubes he was using without a collision. 
His nioststriking experiments were made on cathode rays, a 
name given by the German physicist, Goldstein (who spent 
a long life in studying the electrical properties of gases), to 
something travelling in straight lines from the cathode 
when an electric current passed through a gas at low 
pressure, and producing phosphorescence when they strike 
against the walls of the box. They were first observed by 
Pliicker in 1859. The nature of these rays became almost 
an international question. The German physicists, with the 
significant exception of von Helmholtz, regarded them as 
waves ; the English, I think without exception, thought 
they were atoms or molecules of the gas charged with 
negative electricity. The contest between these views went 
on with great vigour. Further rcscarda has shown that 
neither side was wholly right nor wholly wrong. The 
cathode rays are particles charged witli negative electricity, 
but these particles arc not atoms or molecules, but electrons 
— very much smaller bodies — and these electrons arc ac- 
companied by waves. 

Crookes was a very skilful experimenter and he had 
the gift of arranging his experiments so tliat, in addition 
to their scientific importance, they were among the most 
striking and beautiful spectacles known in physics. With 


these he delighted, almost yearly, crowded audiences at 
the Friday Evening Discourses at the Royal Institution. 
His experiments led him to the conception of a fourth 
state of matter, a state in which the molecules were so 
far apart that they could travel across the vessel in which 
they were contained without coming into collision with 
other molecules. He said, and said quite truly, that when 
this is the case the properties of the gas will be quite 
different from those of a gas at higher pressures, when the 
molecules can hardly stir without hitting against other 
molecules. This is a necessary and very interesting con- 
sequence of any molecular theory of gases, and it vras 
never more beautifully illustrated than by Crookes’ ex- 
periments. It does not, however, tell us anything about 
the molecules. It was discovered later that the cathode 
rays were not molecules but very small particles called 
electrons, which had been knocked out of the molecules 
of the gas, and that these small particles were of the same 
kind from whatever kind of molecules they proceeded, 
showing that the electron is a constituent of every kind 
of substance. Crookes himself became a convert to the 
electron theory and said, “ What was puzzling on the 
radiant matter theory is now precise and luminous on 
the electron 

Crookes was in many ways unlike other English men 
of science. His well-waxed moustache gave him a some- 
what foreign appearance ; he was not, as most of them 
were, comiected with any university or college. He was 
a director of public companies, the proprietor and editor 
of a journal, gas inspector and expert witness, and at one 
time he owned a gold mine ; he did his work in a 
laboratory of his own. His training, too, had been dif- 
ferent from that of his contemporaries. He left school 


when he was fifteen and went to the Royal College of 
Chemistry, where Hofmann, an eminent organic chemist, 
was Professor, Here he specialised in chemistry, and 
showed the individuality which was characteristic of him 
by working at inorganic chemistry, while the other pupils, 
including Perkins, the discoverer of aniline dyes, followed 
the example of the Professor, and worked at organic. His 
knowledge of mathematics was of the most rudimentary 
description, and he Jiad never been through any course 
of instruction in physics. He picked up his physics as he 
wanted it for the research in which he was engaged, and 
could rely on being able to get Stokes’ advice when he 
got into difficulties on theoretical questions. Stokes took 
great interest in his experiments and had a very high 
opinion of them ; he says (Memoir of Sir Ccorj^e Gabriel 
Stokes, by Sir Joseph Larmor, voL i. p. 353), “For 
enlarging our conceptions of the ultimate wc^rking of 
matter, I know nothing like what Crookes has been doing 
for some years ”. In the second volume of the Memoir 
some of Stokes’ letters to Cnn^kes arc printed. They 
cover 133 pages ; on one occasion at least there were two 
on one day. Crookes found Stokes’ handwriting so diffi- 
cult to read that he had to call to his aid the head printer 
of the Chemical News, ajournal which Crookes had founded 
in 1861, and of which he was then proprietor and editor. 

Stokes, it may be said, was one of the first to use a 
typewriter, but these were not available in time for the 
earlier letters. I remember hearing Stokes urging J. C. 
Adams to get one, and Adams said, “ Why should I ? 
People can read my writing/’ 

Crookes’ success was due not only to his skill as an 
experimenter, but also to his powers of observation. He 
was very quick to observe anything abnormal and set to 


work to get some explanation. He tried one thing after 
another in the hope of increasing the effect, so as to make 
it easy to observe and measure ; his work on the radio- 
meter and the cathode rays arc striking examples of this. 
In his investigations he was like an explorer in an unknown 
country, examining everything that seemed of interest, 
rather than a traveller wishing to reach some particular 
place, and regarding the intervening country as something 
to be rushed through as quickly as possible. 

Between his investigations on thallium and those on 
the radiometer, i.e. between 1870 and 1874, Crookes was 
mainly occupied with investigations on what he called 
“ psychic force ”, which excited the interest of the public, 
and much criticism and obloquy from the great majority 
of men of science, who maintained that tlae results were 
worthless, and were produced by fraudulcncc on the part 
of the mediums. Now after sixty years, in whicli there 
have been many investigations made on the subject, 
opinion is much the same. Sir Oliver Lodge maintains 
that though a medium may be detected in fraud it docs 
not necessarily follow that he has no psychic power. 
His view is that the medium is out to produce certain 
results, and that he will produce them with the least 
expenditure of effort, and, if the control is so lax that it is 
easier to produce them by conjuring than by his psychic 
powers, he will conjure. 

The phenomena observed by Crookes were produced 
by mediums all of whom at one time or another had been 
detected, or had confessed to using fraudulent methods to 
obtain their results. By far the most important of these 
was D. D. Home, an American who came to London in 


1869, and gave spiritualistic seances which became very 
fashionable and were very largely attended. He must 
have had very attractive manners ; he won the ajffection 
and confidence of Crookes and his wife ; he was adopted 
as a son by a wealthy lady who is said to have lavished 
^50,000 upon him (which she afterwards tried to get back) ; 
he was the Mr Sludge in Browning’s poem, “ Mr Sludge 
the Medium He was a medium of quite exceptional 
power, and had the great merit of being able to produce 
his effects in the hght. This, of course, made trickery 
much easier to detect. Some conjurors, however, can 
do their tricks in a good light by distracting the attention 
of the observers. When dealing with mediums whose 
honesty is not beyond question it is necessary, before 
we can attach importance to their results, to be sure that 
no such distractions have taken place. Some of the most 
striking of Home’s results could have been produced by a 
movement of a finger through a few inches. The possi- 
bility of hallucination cannot, I think, be regarded as alto- 
gether impossible. On page 265 of the Life of Lord Ray- 
leigh, by his son, there is the following passage : “ Lady 
Crookes . . . mentioned that at their seances they had 
been sitting round a particular table for some days, then 
they put it aside and took another. The first table came 
out from its comer apparently to attack the other, which 
leaped on to the sofa, was pursued by the first and they 
had a fight there. Crookes, when appealed to, said he 
knew nothing about motives, but corroborated the facts.” 

The phenomena obtained by Home were physical 
ones, tilting of tables, playing on accordions, production 
of floating luminosities and the like. Crookes’ view was 
that these were not produced by spirits but by something 
coming from the medium himself, which he called psychic 


force. This force he supposed to act much as ectoplasm 
does in some modem theories. 

The experiments which he describes were made in his 
dining-room, which was lit by a gas-jet of about 5 candle- 
power. The simplest and most important experiment 
was that supposed to prove that Home could alter the 
weight of a plank. A plank about 10 lbs. in weight 
was supported in a horizontal position : one end was 
attached to a spring balance to register its weight ; 
the other end rested on a knife-edge, which stood 
on a table, and in the experiments Home was sup- 
posed to press on the part of the plank between its 
free extremity and the knife-edge. Crookes and his 
wife sat on either side of him to see that the pressure was 
applied at this place, and wnth one foot on the foot of 
Home nearest to them. Under these conditions the 
spring balance indicated an increase of weight amounting 
in one case to nearly 12 oz. Crookes in June 1871 com- 
municated to the Royal Society a paper containing an 
account of this and some other experiments made with 
Home. The Committee of Papers, at their first meeting 
after the receipt of the paper, postponed their decision for 
a fortnight. Crookes heard of this : he wrote at once to 
Home : ‘‘I want you therefore to help me by giving 
me three evenings, between now and the 27th inst., at 
which I can repeat the increase of weight experiment in 
the presence of one or two other good witnesses, and then 
send in on the 28th an overwhelming mass of evidence 
which the committee can’t reject”. He sent in a further 
paper on June 28 th, but it does not seem to have contained 
an account of any further seances with Home. The paper 
came before the Council of the Society and was unani- 
mously rejected. This course seems to me to have been 



entirely justifiable. Here was a discovery of stupendous 
importance, and at first sight of the utmost improbability, 
while the value of the evidence depended on the good 
faith of Home, a man of whose honesty there were grave 
suspicions, though Crookes believed in him implicitly. It 
is true that the experiments were not made in darkness 
and that some precautions were taken against fraud, but 
were these such as to make fraud impossible ? Might not 
Home sometimes succeed in distracting the attention of 
the observers and then do his trick ? He ran very little 
risk, for if he could at a seance not manage to elude the 
vigilance of the others, he had only to refrain from doing 
anything and say that his psychic power had failed. 
Crookes in a letter to Huggins says : “ Home was in 
wonderful form last night, but he is the most uncertain 
of mediums, and it is q^uite as likely that the next time 
absolutely nothing will take place 

Crookes pubhshed what were substantially the papers 
he sent to the Royal Society, in the Quarterly Journal of 
Science and also in the Chemical News. These met with 
severe criticism, which Crookes answered with much 
vigour ; he proved to be an excellent controversiaHst. 
His account of an interview he had with one of his most 
persistent critics. Dr. W. B. Carpenter, who was rather 
long-winded and had no inferiority complex, is very good 
reading. It is given in Fournier d*Albe, Life of Crookes, 
p. 213. 

Crookes’ active work on spiritualism was confined to 
the years 18 70-74, when he returned to physics and dis- 
covered the radiometer. He retained, however, his belief 
in it imtil the end of his life and tried, after the death of 
his wife, to get into communication with her through 
a medium. He avowed his behef on many occasions ; e.g. 



ill his Presidential Address to the British Association at 
Bristol in 1898 he said : “ I have nothing to retract ; I 
adhere to my already published statements. Indeed I 
might add much thereto.* * It is more than sixty years since 
Crookes gave up psychical researches, and we do not seem 
any nearer a conclusive proof of their reality than we were 
then. The aid of infra-red Hght has recently been used to 
determine what is going on in dark seances, but the results 
obtained so far are inconclusive. If we could get infra- 
red light intense enough to produce photographs with very 
short exposure, we might “film” a dark seance and detect 
any cheating in that way. As far as I know, no undisputed 
record of any spirituaHstic phenomenon has been obtained. 
I have quoted Crookes* allusion to spirituaHsm in his 
Presidential Address : the subject turned up again at the 
same meeting, in a much less formal manner, at the Red 
Lion dinner. This is a function which occurs near the end 
of the meeting, whose aim is to get amusement rather than 
instruction out of the proceedings of the Association. 
Each President has a shield, with his name, crest and motto 
displayed upon it, hung on the walls of the reception room. 
The motto on Crookes* shield was “ Ubi Crux, ibi Lux ’*. 
At the Red Lion dinner a distinguished chemist got up and 
unrolled somewhat nervously a shield which was a copy 
of Crookes’ shield in everything except the motto, which 
was changed to “ Ubi Crookes, ibi Spooks ”. Crookes 
took this in very good part. 

The interest taken m the subject of the passage of elec- 
tricity through gases began to increase rapidly towards the 
end of the seventies. This was to a large extent because 
its vital importance in connection with the structure of 
molecules and atoms was beginning to be reaUsed, and 



also because the phenomena associated with it were very- 
various and of exceptional beauty. In England, besides 
Crookes, De la Rue and Hugo Muller, Spottiswoode and 
Moulton, and in Germany, Goldstein and Hittorf, made 
important advances at this early stage. Both De la Rue 
and Spottiswoode were of a class which has made more 
important contributions to science in this comitry than it 
has in any other. I mean the class who pursue science as 
a hobby and not as a profession, who work in laboratories 
of their own, and whose experiments are made at their own 
cost. Joule, who measured the mechanical equivalent of 
heat, was a brewer ; Darwin a country gentleman. This 
class is not so numerous as it was-, as the costs of a physical 
laboratory are so great that only very rich men can afford 

De la Rue was the head of a great firm of manufactur- 
ing stationers, known all over the land since their name 
appeared on most of the playing-cards used in this country, 
and Spottiswoode was the head of a very large printing 
business. The experiments of De la Rue and Muller on 
the very interesting and beautiful phenomenon known as the 
“ striated discharge ” are of exceptional interest, and the 
plates they published in the Philosophical Transactions are 
still the best pictures we possess of this phenomenon, and 
have been reproduced in most textbooks dealing with 
electric discharge. This is probably because they used, 
for producing the discharge, a battery of a very large 
number of chloride of silver cells, which give a steadier 
current than induction cods, and, as the striations are 
steadier, the photographs have better defmition. The 
Friday Evening Discourse at the Royal Institution at which 
De la Rue gave an account of these experiments was on a 
heroic scale. The preparation of the experiments for the 



lectiire took, I believe, nine months ; a battery of 18,000 
cells was set up in the Institution, and it was rumoured that 
many hundreds of pounds had been spent on the prepara- 
tion. I have no difficulty in beheving it. The weather 
unfortunately was wretched. 

The two papers by Spottiswoode and Moulton on 
“ Intermittence in the Electric Discharge ” (Phil. Trans., 
Part I, 1879, Part II, 1880) have never received the 
attention which I think they deserved. This may be 
because they are both very long and rather soporific. 
In spite of this they contain much that is valuable. It 
is interesting to note that, though Moulton was a Senior 
Wrangler and Spottiswoode President of the London 
Mathematical Society, there is not in these two long 
papers a mathematical symbol from beginning to end. 
The experiments described in these papers, and which 
gained for him the Fellowship of the Royal Society, were, 
as far as I know, the only experiments Moulton ever 
made. He had made none before either at school or 
Cambridge. They were made soon after he went down 
from Cambridge and whilst he was preparing for the Bar. 
After he had been called he rapidly acquired a very large 
practice, and had no time for research. His mind worked 
with wonderful rapidity ; the marks he got in the Mathe- 
matical Tripos when he was Senior Wrangler were more 
than double those of the Second Wrangler, who became 
a very eminent mathematician. I witnessed a striking 
instance of his mental agility, as I was in court during the 
trial of a suit which the owners of the patent for the “ three 
wires sytem ” of electric wiring brought against various 
electric hghting companies for alleged infringement of this 
patent. The patent had been taken out by Dr. John 
Hopkinson, but he did not at the time attach much im- 

385 2C 


portance to it, and sold it for a very moderate sum. It 
turned out, however, to be exceedingly valuable and many 
millions were involved in the trial. The Bar on either 
side was about three deep in Q.C.’s (it was in Queen 
Victoria’s time), and Moulton was leading for the in- 
fringers. The plaintiffs called Lord Kelvin (then Sir 
William Thomson) as a witness on their side. After his 
examination-in-chief Moulton got up to cross-examine. 
He really had a very poor case, and at first seemed to be 
asking questions without any coimection with each other. 
In answering one of these, a quite simple one, Thomson 
made an unaccountable slip and Moulton sprang at him in 
a flash : “ Sir WiUiam, you say this Thomson had only 
said it a few seconds before, so he said he had. “Then”, 
said Moulton, “ this follows ” ; and it certainly did. From 
this admission he got another as a logical sequence, and so 
on, until these together seriously damaged the plaintiffs’ 
case. Now he could not have foreseen that Thomson 
would make this slip, yet when it came he saw in a moment 
how to turn it to account. It was very interesting to watch 
how he went on from one step to the next, never letting 
Thomson get in sight of his first answer again. But this 
was not the end : when Thomson came out of the box 
some of his friends told him what he had done. He 
was very much perturbed and demanded to be recalled, 
and somehow or another he managed to be so. When he 
got into the box again, he lectured the Bench and the Bar 
for half an hour on the elementary principles of electricity, 
and nobody could get a word in. Counsel on the other 
side were jumping up every other minute saying, “ My 
Lord, what has this to do with the case ? ” “I don’t 
know 1 I don’t know ! ” said the Judge, and Thomson 
went on. 



The importance of the work done by Lord Moulton 
during the war in organising the supply of high explosives 
for our troops can hardly be exaggerated. As soon as the 
war began, it was reahsed that the use of high explosives 
was to be on an altogether different scale from that of any 
previous war. Lord Moulton spent four years of unin- 
terrupted work in providing our troops with an adequate 
supply. New workshops had to be built, others which 
had been used for other purposes adapted : the provision 
of the raw materials for the explosives was a matter of 
vital importance and great difficulty. Lord Moulton’s 
efforts were so successful that the output, which at the 
beginning of the war was only one ton a day, rose to a 
thousand tons before the end. 

Electrolytic Dissociation 

In 1887 views about the nature of solution were put 
forward by Arrhenius and Van’t Hoff which excited great 
interest and led to much discussion. They arose from ex- 
periments made by the botanist Pfeffer on what is known 
as “ osmotic pressure There are membranes such as 
bladder or copper ferrocyanide which act like filters : 
they are permeable by water but not by substances dis- 
solved in it. If such a membrane is placed between a 
solution and pure water, water will flow through the 
membrane from the water into the solution. To stop 
this flow a definite pressure must be apphed to the solu- 
tion ; this pressure is called the Osmotic Pressure of the 
solution. Pfeffer’s experiments attracted the attention of 
van’t Hoff, one of the most brflhant figures in the history 
of chemistry. In 1874, when he was only twenty-two, he 


published a paper which was translated into French a year 
afterwards, with the title “ La Chimie dans TEspace ”, 
which may fairly be said to have been the origin of a 
large part of the work done in organic chemistry since 
its pubhcation. He studied Pfefler’s measurement of the 
osmotic pressure of sugar solutions of various strengths and 
showed that, within the errors of experiment, “ the osmotic 
pressure is equal to the pressure which a gas would exert 
if the number of its molecules per c.c. were equal to the 
number of molecules of sugar in the same space He 
went further. Pfeffer had made measurements of osmotic 
pressure at different temperatures, and van’t Hoff showed 
that they followed roughly Gay-Lussac’s law for the 
variation of pressure with the temperature of a gas when 
the volume is constant. This led him to the conclusion 
that in solution the solute is in the form of single mole- 
cules, and that these exert the same pressure as the same 
number of gaseous particles in a volume equal to that of 
the solution. 

The direct measurement of osmotic pressure is very 
difficult except for very dilute solutions. For a solution 
of I gram equivalent per litre it is about 22 atmospheres, 
and semi-permeable membranes which would stand such 
a pressure are very difficult to make. Fortunately, how- 
ever, it follows from thermodynamical principles that the 
osmotic pressure as defined above is proportional to the 
difference between the freezing point of the solution and 
that of water, and that this result is independent of any 
particular theory of how the pressure is produced, so that 
we can find the osmotic pressure by measuring the lower- 
ing of the freezing point. It also follows from thermo- 
dynamics that the osmotic pressure for dilute solutions, 
when the distance between the particles of the solute is so 


large that they do not exert any appreciable action on 
each other, depends only upon the number of the particles 
and not upon their kind, or whether they are all of one 
kind or are a mixture of different kinds. Using the freezing- 
point method, Raoult determined the number of particles 
in I c.c. of the solution. For weak solutions of sugar he 
found that this was equal to the number of molecules of 
sugar. He found, however, that this did not hold for 
solutions of salts and acids which are electrolytes. The 
osmotic pressure for these was always greater than that 
corresponding to the number of molecules of the salt or 
acid, and for very dilute solutions the results indicated 
that it was twice as great. The explanation of this increase 
given by Arrhenius was one of the greatest advances ever 
made in physical chemistry, and was as simple as it was 
daring. The experiments showed that for electrolytes the 
number of particles in the solution was greater than the 
number of molecules put in, hence some of the molecules 
must have broken up. Arrhenius had noticed that the 
electrical conductivity of the solution was proportional to 
the excess of the number of particles above the normal. 
This led him to the idea that when a molecule of a salt 
splits up in a solution it spHts into two particles, one of 
which is positively, and the other negatively, electrified, 
i.e. into positive and negative ions. And that in very dilute 
solutions where there are twice as many particles as there 
are molecules there are nothing but charged ions and no 
molecules. That, for example, in a dilute solution of KCl 
there is no KCl, but only positively charged potassium 
ions and negatively electrified chlorine. This was a very- 
startling result, for potassium itself is so violently acted 
upon by water that a piece of the metal thrown on water 
bursts into flame, and to suppose that an atom of it would 


not be acted upon in the water seemed as reasonable as to 
suppose that a man could escape getting wet by diving 
into the sea. The atom of potassium in the solution is 
not like an atom in the metal ; it is an atom carrying a 
charge of positive electricity. In the light of the electrical 
theory of matter, we regard the violence of the action 
between potassium and water as due to the effort of the 
potassium atom to get a charge of positive electricity ; 
when it has got this it is satisfied and no longer acts upon 
the water. On the theory of electrolytic dissociation, the 
potassium atom has got its positive charge and has no 
inducement to attack the water. At the time when 
Arrhenius published his theory, the effect of an electric 
charge on the properties of an atom was not understood. 
He must have been aware of the difficulties in the way 
of his theory and it was very courageous of him to 
publish the conclusions from which his experiments 
seemed to offer no escape. 

It was quite natural that these difficulties should have 
prevented any general acceptance of the theory, and it met 
with very severe criticism. One prominent English chemist 
wrote, “ Let us not pervert the morals of our students by 
talking glibly about atomic dissociation But though 
most chemists at first opposed the theory, it was sup- 
ported from the beginning by Ostwald, a great German 
chemist, and the general acceptance of the theory was 
largely due to his clear presentation of it, and the experi- 
ments he made in its support. It is said that after reading 
Arrhenius’ paper he went to Stockholm to discuss it with 
him. During the discussion there was a succession of 
taps on the door and Arrhenius went out and returned 
almost immediately- After the interview Ostwald asked 
what was the reason of this, and Arrhenius said that some 


of his friends had heard of the visit, and, knowing what a 
“ leg-up ” it would give the theory, had come to con- 
gratulate him in the usual Swedish way by drinking a 
glass of Swedish punch with him. Swedish punch is a 
very potent drink, but it would have taken more than 
that to muddle Arrhenius. 

In dilute solutions the charged particles are so far from 
one another that the forces between them do not produce 
appreciable effects. In strong solutions, however, they 
will influence the arrangements of the ions throughout 
the solution ; a study of this arrangement is of profound 
interest and importance, and has engaged, and is engag- 
ing, the attention of many eminent physicists. 

Hertz and Electric Waves 

In 1887 Heinrich Hertz, a young German physicist and 
a pupil of von Helmholtz, demonstrated for the first time 
the existence of waves of electric force. This discovery 
was of transcendental importance both for pure science 
and for its apphcation to the service of man. It aroused 
great interest all over the world, and in no place more than 
in the Cavendish Laboratory, for the existence of electrical 
waves had been suggested and their theory developed by 
Clerk Maxwell, the first Cavendish Professor. Maxwell, 
soon after taking his degree, had been very much interested 
in Faraday’s discoveries, and impressed by the extent to 
which he had been guided in making them by his con- 
ception of lines of electric and magnetic force. Faraday 
regarded an electric charge or a magnetic pole as the ter- 
minus of lines of electric force and magnetic force, stretch- 
ing through space from charge to charge or from pole 


to pole. On Faraday’s view these lines of force were the 
origin of electric and magnetic forces. To him they were 
not merely geometrical lines, they had physical properties ; 
they were in a state of tension hke stretched strings 
and thus produced the attractions between oppositely 
electrified bodies or between poles of opposite signs. 
Maxwell’s first paper on electricity on “ Faraday’s Lines of 
Force ” was pubHshed in 1855, and was mainly a translation 
of Faraday’s views into mathematical language. In it he 
showed that these led to exactly the same values for forces 
between electric charges, and between magnetic poles, as 
the old theory of action at a distance. The next contribu- 
tion of Maxwell to electrical theory was given in papers in 
the Philosophical Magazine, 1861 and 1862. In these papers 
he devises a model to illustrate Faraday’s discovery of 
electromagnetic induction, i.e. that changes in magnetic 
force give rise to electric force. No one ever appreciated 
more than Maxwell the advantages gained in concentra- 
tion of thought, and in the suggestion of new ideas, by 
considering a concrete case hke a model, instead of relying 
upon algebraical symbols. He says : “ For the sake of 
persons of different types of mind scientific truth should be 
presented in different forms, and should be regarded as 
equally scientific, whether it appears in the robust form and 
colouring of a physical illustration, or in the tenuity and 
paleness of a symbolical expression ”. 

His model was designed to illustrate the production of 
electric forces by changes in magnetic force. When he 
came to use the model he found that in it changes in 
electric force produce magnetic force. The introduction 
and development of this idea was Maxwell’s greatest con- 
tribution to physics. He showed that it imphed that the 
components of the electric force, as well as those of the 



magnetic, all satisfied the wave equations, and that the 
velocity of the waves was equal to a well-known quantity 
in electrical science called the ratio of the units. It is the 
ratio of the measure of a charge of electricity on the 
electrostatic system of units to the measure of the same 
charge on the electromagnetic system. This ratio had 
been measured by Kohlrausch and Weber some time before 
and found tobe 3-1 x io^° cm./sec., w’hich agreed within the 
limit of errors of experiment with Fizeau’s determination 
of the velocity of hght. On the theories current before 
Maxwell’s, electric waves could not exist, while on his 
theory every change in electric or magnetic force sent 
waves spreading through space with the velocity of light. 
Thus the velocity of light is the same as that of electric 
waves . This at once suggested that light waves were waves 
of electric force, and that their velocity could be calculated 
from purely electrical data. This is the outstanding feature 
of Maxwell’s theory. It is the only theory which tells 
us that the velocity of light is 3 x 10^® cm./sec. Other 
theories such as the elastic soHd theory give expressions for 
it in terms of quantities we do not know, but Maxwell’s 
is the only one which tells us what the velocity of hght is. 

The papers in the Philosophical Magazine are a most 
fascinating account of the birth of a theory. I was so 
charmed by them when a boy that I copied them out 
in long-hand. Maxwell returns to his theory in a paper, 
“The Dynamics of the Electromagnetic Field”, pubHshed 
in 1865. In this the model used in the earUer paper is 
not introduced. It had done its work by suggesting the 
existence of these new effects. In the later paper he postu- 
lates the existence of these effects and develops their con- 
sequences. The final presentation of his theory is given in 
his Treatise on Electricity and Magnetism pubhshed in 1873. 



The part of his theory that attracted most attention was that 
light waves were waves of electric and magnetic forces. 
These waves, however, if Maxwell’s theory is true, are 
only a small fraction of the electrical waves which, though 
we cannot see them, must always be passing through the 
space around us. The detection of these was vital for 
the estabhshment of the theory. It was many years after 
Maxwell’s death before a satisfactory method of detecting 
these was available. W e had to confine ourselves to testing 
whether hght waves, in other respects than velocity, be- 
haved in accordance with Maxwell’s theory. Though the 
results of these were on the whole favourable, they could 
hardly be considered as conclusive, and could not be expected 
to convert the older men, who had been using for years 
other theories which had led them to great discoveries, 
and which were not inconsistent with any known electrical 
phenomena. It was quite different in the case of the 
younger men who were begimiing their study of elec- 
tricity and had no theories to give up. To them the beauty 
of Maxwell’s theory made a strong appeal ; “ beauty is 
truth ”, and there was no evidence that the theory was not 
true. Lord Kelvin’s discovery of the oscillatory discharge 
of a Leyden jar, made long before, gave the means of pro- 
ducing electrical waves if Maxwell’s theory were true. 
The difficulty was that the electric forces in these waves 
would be changing from one direction to the opposite 
millions of times per second, and no instruments were 
known which could make any response to forces of this 
type. These electric forces in the waves may be of con- 
siderable magnitude and could be detected with great 
ease if they kept acting in one direction for an appreciable 
time. Now the spark which passes between two metal 
balls placed close together, though it requires a consider- 


able electric force to produce it, is, when such a force is 
available, produced in a very short time ; tinder favourable 
circumstances in much less than a millionth of a second. 
If the electric force in the wave acts in one direction for 
longer than the spark lasts, it can produce its effect before a 
force in the opposite direction comes to interfere with it. 
It was by using these sparks, and observing the alteration 
of the length of the spark when the spark-gap was placed 
in different positions, that Hertz demonstrated the existence 
of electric waves. He showed that they were reflected 
in the same way as hght waves, that like these they could 
be brought to a focus, polarised, and could produce inter- 
ference effects from which their wave-length could be 
calculated. Younger physicists, using the very delicate 
methods for detecting electrical waves now available, will 
not reahse the difficulty of these experiments, but older 
ones, who hke myself began by using Hertz' method and 
had to observe whether tiny sparks, only a fraction of a milli- 
metrelong, waxed or waned when the detector was moved 
from one position to another, will remember how arduous 
and harassing these experiments were and how long it 
took to make sure that the effects observed were not spuri- 
ous.^ Rough as the method seemed, it was able in Hertz' 

^ A remarkable example of die difficulty of being sure that small 
changes in the intensity of light are real and not subjective is that of the 
N rays, which attracted a great deal of attention at die beginning of this 
century. They were first brought into notice by a distinguished French 
physicist, M. Blondlot, who came to the conclusion that the Hght from a 
Welsbach mande, or Nemst filament, was accompanied by a species of 
radiation which, like Rontgen rays, could pass through substances opaque 
to ordinary Hght but, unHke them, could be refiracted. He called them 
N rays. These rays did not produce Hght by themselves, but when they 
fell on a faindy luminous source of Hght, such as a feeble electric spark or 
a dim patch of phosphorescence, they altered the intensity of the Hght, 
generally, though not always, increasing it. A great many physicists 
tried to verify these effects, but for the most part f^ed to do so. It was 
remarkable that the power of seeing N rays seemed to be confined to 



hands to prove the existence of electrical waves and to 
enable him to establish the theory which Maxwell had put 
forward. The names of Maxwell and Hertz will always 
be associated in the history of this subject. It is remarkable 
that of Hertz’ many experiments, the one that did most to 
convince people of the existence of these waves was that 
which was supposed to be analogous to the production of 
stationary waves in optics or acoustics. This, however, 
turned out not to be the case. In the optical waves the 
distance between the nodes and the loops depends only 
upon the wave-length of the waves. It was found, how- 
ever, that this distance in Hertz’ experiment depended to a 
large extent upon the size of the instrument used to detect 
it. This was traced to the emission of waves by the 
detector itself when struck by the incident electrical waves. 

Another name that should be mentioned in association 
with those of Maxwell and Hertz is that of Sir OUver 
Lodge, who made many very beautiful and striking 
experiments illustrating the vibrations excited when a 
Leyden jar is discharged. The time of these oscillations 
depends on the length of wire connecting the inside and 
outside of the jar, and the jar can be tuned by altering 
this length. If a jar is connected with an induction cod, 

Frenchmen. ; as far as I am aware no English, German or American 
physicist succeeded in finding them, while in France they seemed to be 
universal. Some observers thought they had detected them coming from 
human beings, from plants and frogs, as well as from the luminous flames 
used in the earlier experiments. An incident which occurred at a demon- 
stration of the rays seemed clear evidence that they were subjective [Nature, 
September 29, 1904). An audacious spectator, taking advantage of the 
opportunity afforded by the darkness of the room, managed to twist the 
aluminium prism which was supposed to direct the rays on to the place 
where they were to be observed, into quite a different position. The 
demonstrator continued to locate the rays in the place they were before 
the prism was moved. I believe it is now generally accepted that the effect 
is a subjective one, that the proverb “ Seeing is believing ” is true for them, 
though the interpretation is not the usual one. 



and another jar in its neighbourhood is without any such 
connection, this jar can be tuned by altering the length of 
wire between the outside and inside, so that it sparks when 
the other coil is in action ; when it is thrown out of 
tune by altering the length of the wire, the sparks stop. 
He had also, almost simultaneously with Hertz, obtained 
evidence of electric waves ; his waves, however, travelled 
along wires, while Hertz observed the “ wireless waves 
traveUing through free space. These are the waves which 
now play a large part in the lives of many millions of 
people in this country alone. As an example of how 
the practical appHcations of any scientific discovery may 
exceed the expectations even of those best qualified to 
judge, I may mention that when the Marconi Company 
was being formed Lord Kelvin told me that he had been 
asked to join the board of directors and that he had said 
that he would do so on two conditions. One was that 
OUver Lodge should also be asked, and the second that 
the capital of the company should not exceed ^(^100,000, 
as that, in his opinion, was the maximum amount that 
could profitably be employed in wireless. I imagine he 
thought that the most important use for it would be for 
communication between ships at sea and the land. 


The discovery of Argon is one of the most romantic 
episodes in the history of physics, for it established the 
fact that there is in the atmosphere a gas which had entirely 
escaped notice, in spite of investigations by chemists on 
the composition of the atmosphere, extending over more 
than half a century. This is all the more remarkable 


because the amount of argon in the air is very large, being 
as much as 1*3 per cent by weight. In a cubic yard of 
air at atmospheric pressure there are about 13 grammes of 
argon, so that even a moderately-sized room will contain 
pounds of this gas ; several grammes of it are passing 
through our lungs each hour. A very interesting, im- 
partial and detailed account is given in the Life of Lord 
Rayleigh, by his son. It reads almost like a detective 
story. It begins by Lord Rayleigh finding in 1892 that 
nitrogen prepared from the atmosphere was heavier, 
volume for volume, than that prepared from chemical 
compounds. This suggested that there was some intruder 
lurking in the atmosphere ; the problem was to detect 
him. The first thing to do was to make sure of the 
facts. Lord Rayleigh prepared the chemical nitrogen 
from several different kinds of chemicals, but they all gave 
the same result. Thus the intruder must be in the atmo- 
spheric nitrogen, and it must be heavier than the nitrogen. 
The question was, how did it get there and what was it ? 
Did it come in the preparation of atmospheric nitrogen ? 
To get nitrogen from the air, the oxygen and carbonic 
acid gas must be cleared out. These are processes which 
act, so to speak, as chemical charwomen and clear away 
all the litter from the nitrogen. Had they introduced the 
villain of the piece ? This did not seem possible, for several 
kinds of charwomen were tried and they all left the same 
kind of nitrogen. The thing to do next was to take away 
the real nitrogen and see if anything was left. Cavendish 
long ago had shown that this can be done by mixing the 
nitrogen with oxygen and sending electric sparks through 
the mixture. The nitrogen and oxygen combine and the 
compound they form can be removed by a spray of caustic 
potash. Rayleigh used this method, which, with the 


apparatus at his command, went on very slowly and was 
very laborious, and it required constant attendance, since 
the apparatus for producing the sparks kept stopping and 
needed constant adjustment. The experiment went on 
far into the night, with a telephone arranged near it to 
transmit the noise to him in an adjoining room where 
he was dozing in an armchair. When the noise stopped 
he awoke and went to start the instrument again. The 
diminution in the volume of the nitrogen went on for 
eight or nine days, then became very slow, and ultimately 
stopped. No amount of sparking produced any further 
diminution and the residual gas, when examined by the 
spectroscope, was proved to be neither hydrogen, oxygen 
nor nitrogen. Thus the intruder was at last trapped and 
shown to be a perfect stranger. To make assurance 
doubly sure, Rayleigh tried the same experiment using 
chemical nitrogen instead of the nitrogen from the air ; 
but this completely disappeared, leaving no residue. Thus 
the substance obtained in the first experiment could not 
have been produced by the sparking. Thus, at long last, 
was captured the arch-eluder who had escaped detec- 
tion, though his haunts had been searched continually 
by chemists since chemistry began. He had taken the 
measure of Scotland Yard but had forgotten Sherlock 
Holmes, and when he appeared the game was up. What 
made the discovery especially remarkable was that it was 
made by the use of the balance, an instrument which is, 
and has always been, in every chemical laboratory, and in 
the use of which chemists are very expert. It was not 
discovered, though it might have been, by the spectro- 
scope as so many other elements have been. When the 
properties of argon came to be examined, they were 
found to be very different from those of any other element ; 



roughly speaking, it had no chemical properties, it formed 
no compound with any other element, it would have 
nothing to do with the most tempting brides that the 
chemists put before it ; as this is the trap on which chemists 
rely for catching a new element, it is no wonder that argon 
eluded them. The discovery of argon was much more 
important than the ordinary discovery of an element ; it 
was the discovery of a new type of element, one which 
has been of fundamental importance in the development 
of the theory of the structure of the atom. Sir William 
Ramsay, who had been trying to isolate argon by absorb- 
ing nitrogen by magnesium, and who had succeeded in 
doing so within a few days of Rayleigh’s success with the 
sparking, afterwards discovered helium, neon, krypton, 
and xenon, four other elements of the same type as 
argon. The first announcement of the discovery of argon 
was made by Rayleigh and Ramsay at the meeting of the 
British Association at Oxford on August 13, 1894. h 
was an oral statement and Rayleigh was the speaker. This 
was never published, though some account of it appeared 
in various newspapers. The definitive account of the 
research was given in a paper read before the Royal 
Society on January 31, 1895. After this the existence of a 
new gas in the atmosphere was definitely admitted, though 
rather grudgingly in some quarters. It was quite natural 
and reasonable that chemists should be sceptical about the 
existence of a gas which was present in large quantities in 
the atmosphere but which had never been detected by 
any chemist, and whose properties seemed to be contrary 
to those of other gases. Thus argon, though its density 
is greater than nitrogen, is not so easily liquefied, while 
in general the heavier gaseous elements are more easily 
liquefied than the lighter. This fact seemed conclusive to 


Dewar, Rayleigk’s colleague at the Royal Institution, who 
was busily occupied in the liquefaction of gases, and made 
him at first a vehement opponent of the idea of the east- 
ence of the gas. In addition, there was never any love 
lost between Dewar and Ramsay. Criticism was to be 
expected, but what many resented was the contemptuous 
way in which some chemists spoke of the work, and dis- 
missed the existence of argon as impossible because the 
instincts of a trained chemist warned him that it could not 
be true. 

Rontgen Rays 

The discovery of argon was formally announced at a 
tr , ^^ rir.g of the Royal Society in January 1895 ; before 
the year had ended another discovery of pnma^ im- 
portance (that of the Rontgen rays) had been made, one 
which was destined to prove of first-rate importance or 
the study of the structure of atoms and matter. The first 
discovery of these was not, like that of argon, the resdt 
of long and laborious investigations; it came almost by 
chance. One day in the autumn of 1895 Professor 
Rontgen was experimenting in his laboratory at Wurz- 
burg to see if a Crookes tube, containmg gas at a very low 
pressure, would give out invisible hght if a cuirent of 
electricity went through it. He had covered up the tube 
■with black paper to shield off the visible light, and wm 
omcTpA to find that when he sent the current through the 
tube a piece of cardboard covered with powdered fluor- 
escent substance shone out with a glow bright enough 
to be easily visible. Something must have come out of 
the tube, got through the black paper and reached the 
fluorescent screen. Ultra-violet Hght of any known type 
Am ^ ^ 


could not have done this, as it is more easily absorbed than 
visible light. Shadows were cast on the fluorescing sub- 
stance when a body was placed between the bulb and the 
screen. The shape of the shadow showed that the rays pro- 
ducing it travelled in straight lines from the bulb, and that 
they started from the place where the cathode rays in the 
tube struck against the anode, which in this tube was right 
opposite the cathode. It was soon found that the rays 
from the tube affected a photographic plate ^ so that a 
permanent record of the shadows cast by any object could 
be obtained. Dense objects cast a blacker shadow than 
light ones, so that in, e.g., the shadow of a hand, the bones 
stood out very distinctly against the flesh. Indeed, when 
the pressure in the tube was very low, the flesh could 
hardly be distinguished on the photograph. Similarly, 
the shadow of a purse showed the money in it, but not 
the purse itself. The importance of this property of the 
rays for surgery was at once realised by doctors ; indeed 
Rontgen’s first paper on his rays was read before the 
Medical Society at Wurzburg. 

We organised a scheme at the Cavendish Laboratory 
by which photographs of patients brought by doctors 
were taken by my assistants, Mr Everett and Mr Hayles. 
The results were sometimes disconcerting to the doctors. 
They often showed that broken bones had not been set 
properly, and that the two ends were separated by a wide 
interval and connected only by a callus. One of the 
patients was a prominent member of the University who 
could express himself strongly. He had broken his arm 
and, as it did not heal, he insisted on having it Rontgen- 

* One observer had noticed that his photographic plates got fogged 
when they were near a discharge passing through a gas at low pressure. 
All he did was to move the plates further away ; he saved his plates but 
lost the Rontgen rays. 



rayed and brought his doctor with him. My assistant 
came back after a shorter time than usual. I asked him 
why. He said, “ I came away because I thought the 

doctor would not like me to hear what Mr was 

saying to him after he saw the photograph”. 

A Rontgen-ray installation is now part of the equip- 
ment of every hospital. Few have done more to reheve 
human suffering than Rontgen and those who, by develop- 
ing the apphcation of the rays to surgery, have suppHed 
the surgeon with his most powerful means of diagnosis. 

The rays, as they well might, aroused much general 
interest. They seemed a long way towards the fulfilment 
of Sam Weller’s need for a pair of patent double milhon 
magnifyin’ gas microscopes of hextra power — able to see 
through a flight of stairs and a deal door”. 

Never, perhaps, has a discovery of first-rate importance 
been so quickly and so abundantly verified as that of the 
Rontgen rays. The apparatus required was so simple (an 
induction coil, a Crookes tube and a photographic plate) 
that it v/as at hand in every physical laboratory, and there 
were few of these in which experiments on the rays were 
not started. Many interesting properties w=^ere discovered, 
often practically simultaneously in different laboratories. 
At the Cavendish Laboratory we soon found that when the 
rays pass through a gas they make it a conductor of elec- 
tricity ; they produce positively and negatively electrified 
particles in the gas which move under the action of an 
electric force. I had been studying the conductivity of 
gases under^lectric forces for some time, but had been 
much hampered by the difficulty of finding any method of 
producing the conductivity 'which was efficient and reh- 
able. The new rays removed this difficulty : they could 
be appHed to gases at all temperatures and pressures, and 



could be standardised by observing how much they were 
diminished in intensity by passing through a sheet of tin- 
foil of definite thickness. Experiments which had been 
impossibly difficult before the discovery of the rays be- 
came easy. 

We made at the Cavendish Laboratory many attempts 
to see if the rays which had passed through a thin plate of 
tourmaline would, as light would, show traces of polarisa- 
tion, but never succeeded in finding any such effect. The 
polarisation of Rdntgen rays was proved some years later 
by Professor Barkla. Many researches were made to try 
to distinguish between various views which had been put 
forward as to the nature of the rays. The views which 
received the most support were : 

(1) That they were longitudinal vibrations in the ether. 
The argument in favour of this was that if they were 
vibrations in the ether, they must be longitudinal, other- 
wise they would show traces of polarisation. As soon as 
polarisation was discovered this argument lost all its force. 

(2) That the rays were a form of ultra ultra-violet light, 
the wave-lengths being very much less than any ultra- 
violet yet discovered. It was not a valid objection to this 
view that, while ultra-violet light was both more absorbed 
and more refracted when passing through matter than 
visible light, the Rontgen rays behaved in quite the opposite 
way. The absorption and refraction of visible light by 
matter may depend upon resonance between the vibrations 
of the hght and those of the matter, and this would dis- 
appear if the vibrations of the hght were much more rapid 
than those of the matter. The view now generally held 
is that Rontgen rays may be regarded as ultra-violet light, 
stress being laid on the ultra. 

(3) Another view, first put forward by Stokes, was 



that Rontgen rays are thin pulses, differing from light as 
the sound of a flash of lightning differs from the roll of the 
thunder to which it gives rise. The absence of refraction 
was, in his view, due to the shortness of the time the forces 
in the thin pulse acted on the molecules of the refracting 
medium, that this was so short that only an infinitesinial 
amount of energy would go from the pulse into the 
refracting substance, too little to affect the velocity of its 
propagation. If, instead of a pulse, a long train of waves 
were passed through the substance, a state of equilibrium 
might be expected to be reached, in which a finite amount 
of energy went into the refracting substance and would 
give to it its refracting power. I worked at the problem 
from the other end and calculated what effects would, on 
Maxwell’s theory, be produced if a moving electrified 
charge were suddenly stopped. This calculation showed 
that a pulse of electric and magnetic forces would be 
produced, that the energy in it would be inversely propor- 
tional to its thickness, which would be the distance light 
would travel in the time taken to stop the charged particle. 
The energy flowing through a closed surface surrounding 
the electron would be ajd times the energy possessed by 
the electron before it was stopped, where a is the radius 
of the electron and d the thickness of the pulse. 

The atom on modem views is not an impenetrable 
sphere, but a positively electrified nucleus surrounded by 
electrons, the volume occupied by the electrons and the 
nucleus being an exceedingly minute fraction of the 
volume in which they are enclosed ; in fact, the atom is 
chiefly holes. Under these circumstances it is clear that it 
is a matter of chance how long a collision may last, and 
therefore how thick the pulse it produces may be. Thus 
the radiation given out by a substance bombarded by 


cathode rays is analogous to the radiation given out by an 
incandescent body, and consists of a mixture of Hght of 
different wave-lengths, the proportions of the different 
waves being determined by statistical considerations. One 
thing is clear, that the energy in a pulse cannot be greater 
than the energy in the cathode ray which produces it, and 
since the energy in the pulse is inversely proportional to 
its wave-length, there will be a lower Emit to the wave- 
length of the Rontgen rays given out by bombardment by 
cathode rays ; at this limit the energy in the pulse is equal 
to that possessed by the fastest cathode ray striking the 
target. A few years later an old student of mine, Professor 
Barkla, now Professor of Physics at the University of 
Edinburgh, showed that the resemblance between Rontgen 
rays and light was even more complete than had been 
realised, and he showed that Rontgen rays could be polarised 
and, what was even more important, that each chemical 
element gave out a characteristic Rontgen ray spectrum 
when bombarded by cathode rays whose energy exceeded 
a certain limit. This was in addition to the continuous 
spectrum corresponding to thermal radiation. If, for 
example, we bombard silver with cathode rays, beginning 
with those of small energy, at first the only radiation is the 
continuous one, but if we increase the energy of the 
cathode rays we reach a stage when this is supplemented 
by a Rontgen radiation (A) of definite wave-length ; 
continuing to increase the energy of the cathode ray, we 
get for a time the continuous radiation and (A), but when 
the increase has reached a definite value we get a new type 
of radiation (B), having a smaller wave-length than (A), 
and by increasing the energy we may get other types of 
radiation. The radiations (A), (B) were called by Barkla 
the characteristic radiation of the substance bombarded. 



They correspond to the lines in the visible spectrum of the 
various elements. This was a discovery of fundamental 
importance which was most deservedly rewarded by the 
award of a Nobel Prize. 

Diffraction of Rontgen Rays 

In the diffraction gratings used for spectroscopy the 
rulings are not usually separated by less than lo'"^ cm., 
while the wave-length of the characteristic Rontgen 
radiation of silver, for example, is at ordy about 
of this. It is evident that it would be as likely to get 
diffraction of Rontgen rays from such a grating as to get 
diffraction of light from a grating with the rulings i cm. 
apart. Laue, however, realised that, since in a crystal 
the atoms are arranged periodically at intervals equal to 
the distance between two molecules, a crystal ought to 
act as a diffraction grating for wave-lengths comparable 
with this distance. He directed a beam of Rontgen rays 
on a crystal, and obtained well-marked diffraction effects, 
from which he was able to calculate the wave-length of 
the Rontgen rays. These proved to be exceedingly small 
compared with the wave-length of visible Ught, thus the 
wave-length of the hardest characteristic radiation from 
silver is only about one ten-thousandth part of the wave- 
length of the D line of sodium. Moseley, a pupil working 
in Lord Rutherford’s laboratory in Manchester, obtained 
the very important result that the square of the frequency 
of the hardest radiation given out by an element was a 
linear function of the atomic number of the element. 
From this law we can find the atomic number of any 
element whose characteristic radiation has been determined, 


and thus find if any elements remain to be discovered. 
This was one of the most briUiant discoveries ever made 
by so young a man, and science suffered a grievous loss 
when he fell in the war a few months after publishing his 

Instead of using a crystal to determine the wave-length 
of a characteristic radiation, we may use the diffraction 
pattern given by Rontgen rays of known wave-length, to 
determine the arrangement of the different atoms in a 
molecule of a compound which exists in a crystalline form. 
This method, in the hands of Sir W. H. Bragg and his 
son Professor W, L. Bragg, has developed into a method 
of great power and importance. It is very satisfactory 
to find that in many cases it leads to the same results 
as the chemists had arrived at by purely chemical con- 

The Rontgen rays naturally were the subject of many 
public lectures and of discussions organised by scientific 
societies. I was appointed Rede Lecturer at the Univer- 
sity of Cambridge in 1896 and took them as the subject of 
a lecture to a very large audience. They naturally played 
the leading part in the proceedings of Section A at the 
meeting of the British Association in Liverpool m 1896, 
the first meeting after their discovery. I happened to be 
President of the Section and there was a large gathering 
of physicists, including Lord Kelvin, Sir G. G. Stokes, 
Professor OHver Lodge, Professor G. F. Fitzgerald, and, 
as guests of the Association, Professor Lenard of Heidel- 
berg and Drs. Elster and Geitel of Wolfenbiittel. 

The discussion on Rontgen rays began with a paper 
by Professor Lenard, who was the first to detect rays out- 
side a Crookes tube. These, however, were not Rontgen 
rays but Cathode rays which had passed through a window 


of very thin gold leaf in the tube. Sir George Stokes 
gave a beautifully clear and animated exposition of his 
theory of Rontgen ray. 

Among the guests of the Association were Drs. Elster 
and Geitel, who furnish the most remarkable instance on 
record of a lifelong partnership in research in physics 
extending over forty years. They were boys together at 
the same school ; for thirty-nine years they were both 
teachers in the secondary school at Wolfenbiittel ; they 
lived the greater part of their lives in the same house, which 
had a well-equipped physical laboratory where their re- 
search was done, and though they were offered a dual 
university chair they preferred to stay at WoLfenbiittel. 
Their work covered a very wide range : conduction of 
electricity through flames, photo-electric effects, problems 
in phosphorescence and in meteorology. It was all of 
very high quality and forms a very valuable and sub- 
stantial contribution to physics. Personally they were the 
most deHghtftJ companions, with charming old-world 
manners. They were both keen gardeners, and in their 
greenhouse they not only grew flowers, but also bred 
highly coloured butterflies to settle upon them. 

It was at the Liverpool meeting of the British Associa- 
tion that Sir William Preece, the electrical engineer to the 
Post Office, announced that a young Italian inventor named 
Marconi had come over with a new method of signalling 
through space, and that the Post Office were giving him 
facihties for testing it. Marconi’s first patent was taken 
out in 1896. The Liverpool meeting was also memorable 
as being the first meeting attended by Ernest Rutherford, 
who had come to Cambridge a short time before as a 
research student. 

As Rontgen rays are fight of very small wave-length 


the nature of light ought to be the same as that of these 
rays. Rontgen rays ionise a gas through which they pass, 
and if the wave front of a beam of these rays were continu- 
ous no molecule in the path of the beam could escape from 
being struck by the rays and all would be equally affected 
by it. We should expect either that no molecules would 
be dissociated or that a large proportion would be. This, 
however, is not the case. In the strongest beam of 
Rontgen we can produce, only an infinitesimal fraction of 
the molecules struck by the beam are ionised. I pointed 
out in the Silliman Lectures that I gave at Yale University 
in 1903 (Electricity and Matter, Scribner) that this indicated 
that the front of the beam could not be continuous, but 
must be more like a series of bright spots on a dark back- 
ground, i.e. that the energy must be concentrated in 
separate bundles. This is a small part of what was after- 
wards known as the Quantum Theory of Light, the other 
part of that theory being Planck’s Law that the energy 
in each bundle is equal to hv. 

The quantum of light must, like a corpuscle on the 
Corpuscular Theory of Light, travel through space with- 
out change, and yet it must, like the train of waves of the 
Undulatory Theory, produce interference phenomena. I 
suggested in a letter published in Nature, February 8, 1936, 
that the quantum is a train of waves, but that the waves 
are of a somewhat different character from those in the 
ordinary theory. The waves I considered were waves 
where the lines of electric force were circles, all these 
circles had their centres on a straight line and their 
planes at right angles to it. I showed that a train of 
waves of this kind would travel out in the direction 
of its axis without suffering any change, thus satisfying 
the first condition for the quantum, while, since the 


quantum is a train of waves, it would produce interfer- 
ence effects. 


“ It never rains but it pours.*’ A few months after the 
discovery of Rontgen rays, Becquerel found that salts of 
uranium, either when crystalline or in solution, affected 
after a long exposure a photographic plate protected by a 
covering opaque to ordinary light, and that they emitted 
radiations which, like “ Rontgen rays when they passed 
through a gas, made it a conductor of electricity **. 
Rutherford, working at first in the Cavendish Laboratory, 
investigated the radiation from uranium very thoroughly. 
He found that the radiation was of two types, one type, 
which he called the alpha type, being absorbed after 
passing through a few millimetres of air, while the other, 
the beta type, could get through more than twenty 
times this distance. He used the electrical method of 
investigating the intensity, measuring this by the ionisation 
it produced in a gas. Uranium is the element of great- 
est atomic weight. Shortly after Becquerel’s discovery 
Schmidt found that the element next in atomic weight, 
thorium, possessed similar properties. 

But most important of all was the discovery by 
Monsieur and Madame Curie of a new element, radium, 
which possessed radio-active powers enormously greater 
than those of uranium and thorium. Madame Curie 
had made a systematic examination of a great number 
of chemical elements and their compounds, and also of 
minerals, to see if they could find other elements exhibiting 
radio-active powers. The investigation of the elements 
and their compounds did not lead to anything new. The 


investigation of the minerals yielded, however, surprising 
results : it was found that several minerals containing 
uranium were more active than the same bulk of pure 
uranium. This suggested that there was something more 
radio-active than uranium in these minerals. They proved 
this in yet another way. They prepared from pure sub- 
stances a body which had the same chemical composition 
as the mineral chalcolite, which is very radio-active, and 
found that this had only one-fifth the activity of the native 

M. and Mme Curie set to work to isolate the substance 
or substances responsible for the very great radio-activity 
of the pitchblendes, the ores from which the greater part 
of the uranium used in commerce is extracted. After 
great labour they succeeded, in 1898, in extracting from 
about two tons of pitchblende residues one-tenth of a 
gram of an intensely radio-active substance which they 
called radium. The amount of radium in the ore is so 
small, about one-thirtieth of a pennyweight per ton, that 
its separation would have been impossible if the radiation 
from the substance itself had not supplied a means for its 
detection far more sensitive than any known chemical or 
spectroscopic test. Even so, the separation required much 
time and work, and as M. and Mme Curie had very small 
means and had to rely upon what they earned by teaching, 
it was a hard struggle for them to find the time and money 
required for this investigation. Having got the radium, 
they lost no time before investigating its properties, M. 
Curie taking the physical and Madame the chemical, and 
for many months hardly a number of the Comptes Rendus 
appeared without the announcement of some new and 
striking property of radium. One made by MM. Curie 
and Laborde was that the temperature of the radium salt 


was always higher than the surrounding atmosphere, show- 
ing that the radium was itself a source of heat. The dis- 
coverers of radium, as well they might, soon received 
recognition from learned socieites. In 1903 , M. and Mme 
Curie received the Rumford Medal from the Royal Society 
and shared with M. Becquerel the Nobel Prize. In April 
1906, M. Curie met with a tragic and fatal accident. He 
was knocked down in Paris by a cab, and a lorry passing 
at the time ran over his head. He was then forty-seven 
years of age. In addition to his work on radium, he had 
made investigations which are classical on the variations of 
the magnetic properties of bodies with temperature. He 
discovered that the coef&cient of magnetisation of magnetic 
substances is inversely proportional to the absolute tem- 
perature, a result which is always called Curie’s Law. He 
made also important investigations on piezo-electricity, 
and it is noteworthy that the electrical measurements which 
made the detection of radium possible were all made with 
an electrometer whose action depended on this property. 
He came to us at Cambridge once when he was visiting 
England : he was the most modest of men, ascribing every- 
thing to his wife, and had a most attractive simpHcity of 

Let us, however, return to Rutherford’s experiments in 
the Cavendish Laboratory on the radio-activity of uranium 
and thorium. Those on uranium gave comparatively 
little trouble; the results got on one day could be repeated 
on the next. The behaviour of thorium, on the other 
hand, was most perplexing and capricious ; changes in the 
surroundings which seemed quite trivial, such as opening a 
door in the workroom, produced a very large diminution in 
the radiation, while, on the other hand, very large changes 
in the physical conditions produced no appreciable effect 



upon it. The radio-activity seemed to act like a contagious 
disease and infect solid bodies placed near the thorium. 
These, however, recovered in time if the thorium were 
taken away. These vagaries turned out, however, to be 
an illustration of the principle that difficulties in the experi- 
ments may be the seed of great discoveries, for Ruther- 
ford, when he went as Professor of Physics to Montreal, 
resumed these experiments and, in his attempts to unravel 
their intricacies, was led to a discovery of fundamental 
importance which was the origin of modem views about 
the processes going on in radio-active substances. This 
discovery was that thorium gives off something which 
he called an emanation, which is itself radio-active, and 
which is m the gaseous state, and can thus be wafted about 
by currents of air, and may settle on solids and make them 
behave as if they were radio-active themselves. The radio- 
activity of the emanation is not permanent, but only lasts 
for a few hours, at the end of which the emanation 
has passed into another non-radio-active substance. The 
emanation behaves like the inert gases helium and argon : 
it does not enter into any chemical combinations, and the 
length of its life is not affected by any influence external 
to its molecules. High temperatures, or even bombard- 
ment by the rays given out by strongly radio-active sub- 
stances such as radium, do not seem to do it any harm, 
nor does it last longer when radiation from outside is 
warded off by surrounding it with thick layers of lead. 
Thus the thorium emanation is an element which has a 
transitory life ; it is hable to be seized with a convulsion 
and give out an a ray, i.e. an atom of helium with a double 
positive charge, and when it has done this it becomes 
another element with smaller atomic weight and different 
properties. This new clement may itself after a time 



change into another. The average Hves of these elements 
vary very greatly ; for some it is only a fraction of a second, 
for others it may he many years. 

On the view that an atom consists of electrons revolving 
round a nucleus, each electron makes in one second more 
than a milHon million milhon revolutions, so that, reckoned 
on a time scale fixed by the time of one of these revolutions, 
a second would be an eternity. To explain phenomena 
occurring at so long an interval, we must find some time 
interval, occurring in an isolated atom, which may be 
comparable with a second or even with many years. 
We cannot do so if there is only one electron in the atom 
— but suppose there are two. Sometimes these may be in a 
straight line with the nucleus, but if their periods of rota- 
tion are very nearly equal, each will have to make a very 
large number of revolutions before they are again in a 
straight line. The interval between two such configura- 
tions gives a time associated with this atom much longer than 
that associated with an atom containing only one electron. 
In an atom containing many electrons there are possibiHties 
for configurations containing several electrons ; the more 
electrons there are in a configuration the longer will be the 
interval between its recurrence, and the increase may be 
very rapid. Now it is possible that the reactions between 
the electrons and the nucleus may be such that for a par- 
ticular configuration of the electrons — for example, if all 
of them were pulling in the same way — the nucleus might 
be distorted from its original stable position to an unstable 
one, and fall from this to another stable position, exploding, 
in fact, and emitting as it does so a large amount of energy, 
which is carried away by one of the constituents of the 
nucleus, the a-particle. The interval between two explo- 
sions, or rather the average time before an explosion takes 



place, may from the preceding considerations be of quite a 
different order from the time of revolution of an atom. 

Wilson Tracks 

The method of investigating the nature of various kinds 
of rays — a rays, /3 rays, y rays, cosmic rays — by “ Wilson 
tracks ”, which is now of paramoimt importance in the 
study of atomic structure, was invented and developed by 
Professor C. T. R. Wilson, F.R.S., at first in the Cavendish 
Laboratory and after the war at the Solar Physics Observa- 
tory, Cambridge, in a research which lasted for more 
than twenty years. He began shortly after taking his 
degree in 1892 by experimenting on fogs, not, it might 
seem, a very obvious method of approaching transcend- 
ental physics. He studied the conditions under which 
fogs are formed. It was known that fogs arc not formed 
under normal conditions unless dust is present. This is 
due to the effect of the surface tension on the evaporation 
of drops of water ; this promotes evaporation, and vnll 
make a drop evaporate when surrounded by air saturated 
with water vapour. The effect increases as the size of 
the drop diminishes. It is evident that this property makes 
the growth of drops from smaller ones of microscopic 
dimensions impossible, for these small drops would evapo- 
rate and get smaller, and the smaller they get the faster 
will they evaporate. They are in the position of a man 
whose expenditure increases as his capital decreases, a state 
of tilings which will not last long. If particles of dust are 
present, the water can condense on their surface, and the 
conditions at its surface are the same as for a drop of water 
the size of the particle of dust ; for particles as large as this 


a small supersaturation will be sujEcient to prevent evapora- 
tion, and when more water is deposited and the drop gets 
larger, the evaporation will get less and less ; the dust 
enables the drop to short circuit the impassable early stages. 

If the drop is electrified, the effect of the electrification 
is the opposite to that of surface tension. An electrified 
drop will not evaporate even if the air around it is not 
saturated, and the smaller the drop the smaller is its 
tendency to evaporate, and the greater the deposition of 
moisture from the air outside. For drops below a certain 
size the electrical effect will be greater than that of sur- 
face tension, and a drop, if formed, will increase imtil 
it reaches the critical size. Thus drops should be formed 
even in the absence of dust if they are electrified. 

In Wilson’s experiment, the air in which the fog is 
produced was contained in a vessel one of whose boundaries 
was a movable piston which could move vertically up or 
down. When the pressure below it was suddenly reduced, 
the piston was very rapidly pushed downwards so that 
the volume of the air in the vessel above the piston was 
suddenly increased. This adiabatic expansion cooled the 
air in the tube, and since the air in the tube was, by being 
in contact with water, saturated before the expansion, it 
was supersaturated after it. Before the dust was removed 
from the air a small expansion was suJficient to produce 
a fog ; as the fog settled it carried some dust down with it, 
and by repeated expansions the dust could be removed. 
When this was done, no fog was produced by expansion 
which produced six- or seven-fold supersaturations, but 
when the gas in the tube was ionised by exposure to Ront- 
gen rays or to the radiation firom radium, a dense cloud 
was produced by a four-fold supersaturation. This 
appeared to be uniformly diffused through the tube. 

417 2E 


Wilson then made a step which was all-important for the 
purposes for which the cloud method has proved so valu- 
able. Instead of looking at the tube under continuous 
illumination, he took instantaneous photographs of the 
tube at a very small interval after the expansion, so small 
that the ions had not time to move more than a very small 
distance from the place where they were produced. If the 
ions were produced by a particle like an a or ^ particle 
passing through the tube, they would be produced along 
the track of the particle, and the drops of water deposited 
on these ions would be all on this track, and a photograph 
of these drops would represent the path of the particles. 

In order to get a stereoscopic ejffect he took two 
photographs simultaneously, using two cameras placed in 
different positions. Specimens of these photographs are 
given in Figs, i, 2 and 3, Plate 11 . In Fig. i the ionisation 
was produced by an a particle. Here the ionisation was so 
great that the path appears continuous : on one of these 
there is a sharp bend showing the a particle had been 
deflected by colUsion with a molecule of the gas through 
which it was passing. Fig. 2 shows the path of a fast J 3 
particle through the gas : here the ionisation is not nearly 
so great as for the a particle and the separate drops can be 
distinguished ; the drops are farther apart with fast ^ 
particles than with slow ones, confirming the result in- 
dicated by theory, that ionisation by moving electrified 
particles diminishes with the velocity of the particle after 
a certain velocity is exceeded. If a magnetic force is 
applied to the particles they will no longer move in a 
straight line but will describe a curve, and the photographs 
would show curved lines instead of straight ones : if the 
particles were negatively charged like electrons they would 
be bent in one way ; if they were positively charged, in 



Fig. 2 


the opposite. It was by observing that in some of his 
experiments there were particles bent in opposite directions 
to about the same extent, that Anderson discovered posi- 
tively charged particles having much the same mass as the 
electron. His results were confirmed and extended by 
the work of Blackett and Occhialini. Fig. 3 shows the 
state of things when the gas is ionised by Rontgen rays. 
Here it will be seen that instead of a single line we have 
a very large number of lines starting from places in the 
gas : this shows that the greater part of the ionisation by 
Rontgen rays is produced by charged particles which are 
ejected from the molecules of the gas when these are struck 
by Rontgen rays. 

This work of C. T. R, Wilson, proceeding without 
haste and without rest since 1895, has rarely been equalled 
as an example of ingenuity, insight, skill in manipulation, 
unfailing patience and dogged determination. Those who 
were not working at the Cavendish Laboratory during its 
progress can hardly reahse the amount of work it entailed. 
For many years he did all the glass-blowing himself, and 
only those who have tried it know how exasperating glass- 
blowing can be, and how often when the apparatus is all 
but finished it breaks and the work has to be begim again. 
This never seemed to disconcert Wilson ; he would take up 
a fresh piece of glass, perhaps say ‘‘ Dear, dear ”, but never 
anything stronger, and begin again. Old research 
students when revisiting the Laboratory would say that 
many things had altered since they went away, but the 
thing that most vividly brought back old reminiscences 
was to see C. T. R. glass-blowing. The beautiful photo- 
graphs that he published required years of unremitting 
work before they were brought to the standard he obtained. 
The method has been quickened up and made automatic 



by other workers, but though they can turn out more 
photographs in a given time, the photographs themselves 
are no better than those got by C. T. R. more than twenty 
years ago. It is to him that we owe the creation and 
development of a method which has been of inestimable 
value to the progress of science. 

Lord Kelvin 

Any notice about the progress of physics in the latter 
part of last century would be like the play of Hamlet 
without the Prince of Denmark if it did not deal with the 
part played in it by Lord Kelvin, who for more than forty 
years before his death in 1907 had been the most potent 
influence in British physics. Of the 661 papers he pub- 
lished, those on Thermodynamics which have already 
been alluded to would, I think, in the opinion of 
most people, be regarded as the most important. This, 
however, was not his own opinion, for he told me that 
before the discovery of radium had made some of his 
assumptions untenable, he regarded his work on the Age 
of the Earth as the most important of aU. In this he calcu- 
lated the loss of heat by the earth due to the radiation from 
its surface of the heat coming up by conduction from the 
warmer parts below. He went into the question as to 
whether the earth could have any internal source of energy 
due to the combustion of the substances of which it was 
composed, and found that if these were known elements 
it would only accotmt for a small fraction of the heat lost 
by radiation. He concluded that “ it is highly improbable 
in the present state of science that any effect of this kind 
could compensate for the loss of heat by radiation”, and in 


that case the time between now and the solidification of 
the earth’s crust could not be very much greater than loo 
million years. This view was attacked vigorously by 
both geologists and biologists, by the first because it was 
inadequate for the deposition of the sedimentary rocks, and 
by the second because it was not suflScient for the develop- 
ment from some form of primordial Hfe of the highly 
developed forms of hfe now existing. On his assumptions 
his conclusions were legitimate, but the progress of science 
makes things which seem highly improbable in one 
generation become firmly estabhshed facts in the next. 
The suggestion that bodies could exist with the power of 
emitting such enormous amounts of energy as do radium 
and other radio-active substances would have seemed, to 
say the least, “ highly improbable” at the time (1862) when 
Kelvin’s paper was written, but within fifty years the 
Curies had discovered radium and Rutherford had shown 
it would materially increase the hfe of the habitable earth. 
It is interesting to think that but for radio-activity the 
world would not be habitable. There are other sources of 
energy which might, like radium, prolong the life of the 
world, e.g. the transformation of protons into positrons 
would hberate large amounts. This, however, would 
not be spontaneous. Since the proton is a stable system it 
would require the expenditure of a considerable amount 
of energy, although but a small fraction of that finally 
fiber ated, to start it. 

Thomson’s services to science received early recogni- 
tion. He was only twenty-two when he was elected to the 
Professorship of Natural Philosophy in Glasgow. He was 
elected a Fellow of the Royal Society in 1851 on the same 
day as Stokes and Huxley (this was before the publica- 
tion of his important researches on Thermodynamics). 



He spent a great deal of time between 1856 and 1866 
on work associated with the laying of the Atlantic cable 
between England and America. His connection with 
this arose from his becoming in December 1856 a 
director of the Atlantic Telegraph Company, formed to 
lay a cable between this Company and the United States. 
He threw himself into this work with characteristic energy 
and enthusiasm ; he solved the problem of finding the law 
which determines the rapidity with which signals can be 
sent through a cable ; he showed that though the current 
at the transmitting end is only kept on for a short time, 
the effect at the receiving end will last far longer. Unless 
the interval between signals from the transmitting is 
greater than the time for their effects at the other end to 
die away, one signal will get confused with the one before 
it, and the messages will get so blurred that they are not 
intelligible. To detect the signals he invented the mirror 
galvanometer, which was far more sensitive than any 
which had been used before. The first attempt to lay the 
cable was made in June 1858. Thomson was in one of 
the cable-laying ships, but he was not responsible for the 
apparatus and methods used as these were under the con- 
trol of Mr Whitehouse, the electrician appointed by the 
Company. The cable was laid in spite of many difficulties 
due to heavy storms, and messages were sent through it ; 
one from Queen Victoria of ninety-nine words took i6i 
hours. The messages coming through the cable got feebler 
and feebler and stopped altogether after about three weeks. 
A second attempt was made several years later when fresh 
capital had been raised, and in this case Thomson was the 
electrician in charge. A new cable was made with the 
copper core larger than in the earlier one and its insulation 
more carefully tested. At the first attempt to lay it, it 


parted in mid-ocean, where the depth was 2000 fathoms. 
It was subsequently recovered, but meanwhile another 
cable had been made, and was successfully laid by 
September 1866. This, as it well might, created immense 
enthusiasm in the country, and Thomson’s fame spread 
throughout the length and breadth of the land. He was 
created a knight. He had done a work which could only 
be done by one who was at once a great physicist and a 
skilled electrical engineer, and who had great determina- 
tion, driving power and enthusiasm. Thomson was not 
only enthusiastic himself, his enthusiasm was contagious. 
When he visited the Cavendish Laboratory he would go 
round and see what researches were being done by the 
students. If there was an experiment in progress he would 
take keen interest in it, get the student to repeat it, and 
make suggestions for other experiments. All this was a 
great stimulus to the students and made for the success of 
the laboratory. His triumph with the Atlantic cable led 
naturally to his service beiug retained as Consulting En- 
gineer by many cable companies. He had also, in part- 
nership with Varley, a practice as Consulting Engineer, 
and he also appeared from time to time in the Law Courts 
as an expert witness. These all made additional demands 
on his time and caused many interruptions in his scientific 
work. He told me once that he rehed on his journeys be- 
tween London and Glasgow for thinking out any physical 
problem on which he was working. 

Few men have obtained great distinction over such a 
wide range of subjects. He was a great physicist and had 
left his mark on almost every branch of physics known in 
his time. He was a great mathematician, and used his 
physics to guide his mathematics and his mathematics 
to give precision to his physics. He was also a great 



electrical engineer. He had been President not only of 
the Royal Society but also of the Mathematical and 
Physical Society, of the Institute of Electrical Engineers 
and of Naval Architects. Besides writing hundreds of 
scientific papers he had taken out more than sixty 

His mind was extraordinarily fertile in ideas. This 
was very evident at the meetings of Section A of the 
British Association, which he sedulously attended, accom- 
panied by Lady Kelvin with a packet of sandwiches in case 
the meeting should be too prolonged. He would often 
get up after some paper had been read and say something 
quite new and always interesting, whether one agreed with 
it or not. If Professor G. F. Fitzgerald, who was also 
full of ideas, and Sir Oliver Lodge, who was unrivalled 
in clear exposition, were also present, one saw the British 
Association at its best. Even in a lecture, if a new idea 
occurred to him, he would start off on a new tack. 
This made them very discursive and often very lengthy. 
It was, or used to be, the tradition that the Friday Even- 
ing Discourses at the Royal Institution should not last 
for more than an hour, and I have known Sir James 
Dewar, when he was Director, walk up to a lecturer who 
had exceeded the hour by ten minutes and say to him, 
“ You must stop Lord Kelvin, however, never paid 
any attention to this rule. He has been knovm to have 
lectured for the hour before reaching the subject of the 
lecture- It was only very rarely that he prepared either a 
lecture or a speech. There was, to the few who were 
already interested in the subject he was talking about, 
generally both charm and interest in these diversions. On 
the other hand, when he was writing an important paper 
he took almost meticulous care in choosing the word 


which would most clearly express his meaning. He was 
not fond of reading scientific Hterature and rehed to a 
large extent on conversations with friends for informa- 
tion about new discoveries. In fact he was a remarkable 
exception to that very important physical principle that 
good radiators are good absorbers. 

His first paper appeared in 1841, and from then until 
his death in 1907 there was no year without a paper, and 
few without many. They cover all branches of physics 
and record some of the greatest discoveries made in his 
generation. He himself, however, was not satisfied, for 
at his jubdee in 1896 he said, ‘‘ One word characterizes 
the most strenuous of the efforts for the advancement of 
science that I have made perseveringly during fifty-five 
years, and that word is failure. I know no more of 
electric and magnetic forces or of the relation between 
ether, electricity and ponderable matter, or of chemical 
aflSnity than I knew and tried to teach to my students of 
natural philosophy fifty years ago in my first session 
as Professor.” Science never had a more enthusiastic, 
stimulating or indefatigable leader. 

Niels Bohr 

At the end of 1913 Niels Bohr published the first 
of a series of researches on spectra, which it is not too 
much to say have in some departments of spectroscopy 
changed chaos into order, and which were, I think, the 
most valuable contribution which the quantum theory 
has ever made to physical science ; most of them, how- 
ever, belong to a more recent period than that covered 
by my survey. 




The germ of the theory of relativity was the experi- 
ment made by Michelson and Morley in 1887 to see if 
they could detect any optical effects due to the motion of 
the earth round the sun. There was reason to beUeve 
N that such an effect might exist, 

I for Maxwell had pointed out 
that if a ray of light starting 
from a point A travelled in 
a' Ml I the direction in which the 
' ' laboratory was moving, and 

was reflected back by a mirror M at right angles to its 
path, the time lag between leaving and returning to A 
would be affected by the motion of the system. For 
suppose / is the distance between A and the mirror M, 
c the velocity of light, u the velocity of the mirror; then 
when the Ught is approaching the mirror the velocity of 
light relative to the moving system is c - w, and the time 
taken to reach the mirror is //(c - u) ; on the return journey 
the relative velocity is c-\-u, and the time taken to get 
back to A is //(r+w) ; the time lag is the sum of these 
terms, i.e, zlcjic^ -u^). Consider now a beam travelling 
along AN nearly at right angles to the velocity w, and then 
reflected from a horizontal mirror at N. The direction 
of AN is adjusted so that the reflected beam and the 
moving mirror arrive simultaneously at A' ; the time 
lag between leaving A and returning to A' is zAN/t and 
also AA'/m ; it follows from this that the time lag is ^ 
2ONIV O being midway between A and A' ; ON 
is the vertical distance of the mirror N from the place 
from which the beam starts. Writing L for ON we see 


that the difference in the time lags when both beams 
return to A' is equal to 

— ) . . (i) 

cV I - u^/c^ \ V I - / 

In the experiments A was a semi-transparent mirror, which 
reflected some light and allowed some to pass through 
it. The horizontal beam was transmitted through the 
mirror A when it started, and reflected from it when it 
came back, the vertical beam was reflected when going 
out and transmitted when it came back : the two beams 
in this way become parallel and there will be a change in 
the interference bands they produce unless the expression 
(i) vanishes. In calculating the effect to be expected, u 
was taken to be the velocity of the earth due to its revolu- 
tion round the sim, the velocity of the sun itself is neglected 
as it is supposed to be small in comparison. The apparatus 
would have detected a difference of lag less than one- 
twentieth of that represented by (i), but no effect at all was 
detected. This could not have arisen from mistakes in the 
measurements of / and L which happened to cancel out the 
real effect, for the instrument could be rotated through a 
right angle when L and / would be interchanged, and 
errors in their measurements if they masked the effect in one 
position would increase it in the other. G. F. Fitzgerald 
and Lorentz both suggested in 1892 that the absence of 
any effect could be explained if the apparatus contracted 
in the direction in which it was moving in the ratio of 
I to Vi - ; this as will be seen by (i) makes the 

effect vanish. This contraction could not be detected by 
measurements made in the laboratory, for the scales used 
to measure these lengths would contract in the same 
proportion, and a length which was equal to the length of 


a metre scale if the system were at rest would still be equal 
to it if the system were in motion. Since strains very 
readily produce double refraction in bodies, Lord Rayleigh 
in 1902 tried if he could detect double refraction due 
to the earth’s motion, but was unable to do so ; an ex- 
periment on the same lines but on a large scale was made 
by Brace in 1904, but again the results were negative. 
Tliis contraction is the same as that indicated by Maxwell’s 
theory (see page 3^7). In 1905 Einstein pubhshed his 
theory of relativity. The object of the theory was to 
establish a relation between a phenomenon in a system 
at rest with one in the same system when it is moving in 
a straight line with a uniform velocity u. Suppose that 
some phenomenon occurs in the system at rest expressed 
by a relation between (x, y, z) the co-ordinates of a point 
referred to fixed axes, and the time t. Then on Einstein’s 
theory this will involve a phenomenon in the moving 
system which can be expressed by substituting for x, y, z 
co-ordinates x\ y\ z', and for t a time t\ connected with 
X, y, and t by the relations, 

, x-ut , , 


where /S is written for 

Solving these equations we see that they are equiva- 
lent to 

y=y , 

so that the equations to transfotm from the fixed system 
to the moving one are of the same form as those to trans- 


form from the moving to the fixed, but the sign of u 
must be changed. Let us take as an illustration the effect 
of motion on the length of a rod. Let the length of the 
rod in the moving system be /, x\ the co-ordinate of 
one end, x\ +/ the co-ordinate of the other, then if x-^, x^ 
are the co-ordinates in a system at rest, we have 

Xi-X 2 ,=^, or 

since j3 is less than one, Xi - x^ is greater than lx, in accord- 
ance with the Fitzgerald and Lorentz contraction. 

Einstein showed that it followed from the principle 
of relativity that the mass of a moving body varies as 
I /Vi - and that the energy is equal to mc^ where m 
is the mass when its velocity is u. 

The relation f leads to some apparently 
very paradoxical results. Suppose that, in a system at 
rest, one event occurs at the time at the place Xj and 
another at the time at the place and that t\ and f ^ 
are the times at which they are observed in the moving 
system, we have 

t j — t ~ ^2~ ~ 

Hence when 

t'l — 1 2 = 0 , ti — — (xj — X 2 ), 

so that ti is not equal to hence the events which are 
simultaneous in the moving system are not so in the fixed 
one. We see too that U - and t\ - may have opposite 
signs, /.e. the event which was first in the fixed system 



may be last in the moving one. Thus, for example, if a 
woman after the birth of one child moved into a different 
neighbourhood before the birth of a second, she might 
appear to have had twins to an observer in a moving system, 
while to an observer in a system moving more rapidly 
the second child would appear to have been born before 
the first. One wonders what the mother would have 
thought of relativity. The paradox, however, ceases 
when we remember that, as an observer of an event at a 
distance does not observe it at the time it occurs, but only 
after the interval required by light to travel to him from 
the scene of the event, his knowledge of distant events 
must always be out of date. Thus if he is observing two 
events at two different places, one nearer to him than the 
other, then though the events occurred simultaneously at 
the two places, he would perceive that at the place nearer 
to him before he did that at the other. When the observer 
is moving, his distances from the two places change, and 
if he is moving so as to approach the place that was at 
first further away and recede from the other, when he 
came to the place where the distances were equal, then 
simultaneous events would take the same time to reach 
him and he would regard them as simultaneous, and when 
he went still further, the one that was at first perceived 
after the other would now precede it. 

The results arising from the principles of relativity 
were so surprising, and its exposition by Einstein so 
masterly, that it excited the interest and admiration of 
mathematicians and also of the general public to an 
extent which had never oven been approached by any 
other mathematical question. Lectures on it attracted 
large audiences, books about it became “ best sellers 
and one was continually being asked by one’s neighbour 


at a dinner party to explain in simple words what it was 
about. Once at the Athenaeum Club, Lord Sanderson, 
who was for long permanent Secretary at the Foreign 
Office, came to me and asked if I could help him. He 
said, “ Lord Haldane has been to the Archbishop (Randall 
Davidson) and told him that relativity was going to have 
a great effect upon theology, and that it was his duty as 
Head of the Enghsh Church to make himself acquainted 
with it ” ; he went on, “ The Archbishop, who is the most 
conscientious of men, has procured several books on the 
subject and has been trying to read them, and they have 
driven him to what it is not too much to say is a state of 
intellectual desperation. I have read several of these myself 
and have drawn up a memorandum which I thought 
might be of service to him. I should be glad if you would 
read it and let me know what you think about it, before 
I send it to him.” I said I did not think relativity had 
anything to do with religion but I would read his memo- 
randum. I see from the biography of the Archbishop by 
the Bishop of Chichester that just about this time the 
Archbishop met Einstein at Lord Haldane’s house, and 
asked him what effect he thought relativity would have 
on religion. Einstein said, “ None. Relativity is a purely 
scientific matter, and has nothing to do with reHgion. 

The theory of relativity deals with physical pheno- 
mena. If we take the view that the structure of matter 
is electric, these ought to follow from Maxwell’s equations 
without introducing relativity. We have referred to 
examples in which various effects have been explained 
in t-bi*; way, e.g. the contraction of a moving body and 
the variation of mass with velocity, before relativity was 
introduced. On this view it is reasonable to regard 
Maxwell’s equations as the fundamental principle rather 



than that of relativity, and also to regard the ether as 
the seat of the mass momentum and energy of matter, 
i.e. of protons and electrons : lines of force being the 
bonds which bind ether to matter. In Einstein’s theory 
there is no mention of an ether, but a great deal about 
space : now space if it is to be of any use in physics must 
have much the same properties as we ascribe to the ether ; 
for example, as Descartes pointed out long ago, space 
cannot be a void. Unless there was something in space 
there would be nothing to fix the position of a point, 
position would have no meaning and space could have no 
geometrical properties ; the same would be true even if 
it were filled with a perfectly uniform substance, for again 
there would be nothing to differentiate one point from 
another. Space must therefore have a structure. Again, 
there must be in space something which changes. If there 
were not there would be nothing to distinguish one instant 
from another, nothing to supply a “ clock ”. Nothing 
can travel through space with a velocity greater than 
light; this is the speed limit for traffic through it, but space 
could not enforce this unless it had some time to measure 
the velocity, and this requires something by which we 
could measure times. Again, the mass of a body increases 
as the velocity increases ; if the mass does not come from 
space it must be created. It would seem that space must 
possess mass and structure both in time and space : in 
fact it must possess the qualities postulated for the ether. 

“ Naturam expellas furca, tamen usque recurret.” 

It has been urged against the existence of the ether that 
so many different kinds of ether have been from time to 
time proposed. The same may be said about “ space ” : 
we have Einstein’s space, de Sitter’s space, expanding 



universes, contracting universes, vibrating universes, 
mysterious universes. In fact the pure mathematician 
may create universes just by writing down an equation, 
and indeed if he is an individualist he can have a universe 
of his own. 

The kind of relativity I have considered, special 
relativity” as it is now called, was Einstein’s first theory 
and deals with electric and magnetic problems which can 
also be solved by Maxwell’s equations. Einstein has 
given a second theory, known as “ general relativity ”, 
which includes a theory of gravitation. This involves 
much very abstruse and difTicult mathematics, and there 
is much of it I do not profess to understand. 1 have, 
however, a profound admiration h^r the masterly way 
in which he has attacked a problem of transcendent 


(i) List of my Cavendish Students who became Fellows 
of the Royal Society 

The first of iny pupils to receive the distmction 
of the F.R.S. was Callendar, who was elected to the 
Society in 1894 ; he was followed in 1897 hy C. Chree, 
now deceased, who made important investigations in 
terrestrial magnetism for which he was awarded the 
Hughes Medal of the Royal Society ; in 1899 R. Threl- 
fall (see p. 117) was elected ; in 1900 C. T. R. Wilson, 
about whose work much has been said already, and for 
which he received the Hughes, Royal and Copley Medals, 
and was awarded the Nobel Prize, was elected ; in 1901 
W. C. Dampier Whetham (now Sir Wilham Dampier) 
was elected for his work on electrolysis. In 1903 E. 
Rutherford (now Lord Rutherford and Cavendish Pro- 
fessor at Cambridge) was elected for his research on 
radio-activity which laid the foundations of that science, 
and for which he received afterwards the Rumford and 
Copley Medals and also a Nobel Prize. In the same 
year J. S. E. Townsend (now Wykeham Professor of 
Physics at Oxford and who came to the Laboratory on 
the same day as Rutherford), was elected for his re- 
searches on the ionisation of gases, which he has carried 
on with great assiduity and success ever since and for 
which he was awarded the Hughes Medal. In 1905 the 
Hon. R. J. Strutt (now Lord Rayleigh) was elected for 
his work on the discharge of electricity through gases and 

435 2P2 


on the radio-activity of various rocks and minerals. He 
has also received the Rumford Medal. In the same year 

G. F. C. Scarle was elected for his work on magnetic 
measurements and on electromagnetic theory. In 1906 

H. A. Wilson was elected for researches which covered a 
wide range of subjects, especially those relating to the 
conductivity of flames, hi 1909 one of the first research 
students, J. A. McClelland (now deceased), was elected 
for his research on the discharge of electricity through 
gases, and on Lenard rays ; in 1912 C. G. Barkla (now 
Professor of Natural Philosophy in the University of 
Edinburgh) was elected for his discovery and investigation 
of the X-ray radiation characteristic of different bodies. 
He afterwards received the Hughes Medal for this work 
and was awarded a Nobel Prize. In 1913 O. W. Richard- 
son, another old student who also later received a Nobel 
Prize and also the Royal and Hughes Medals, was elected 
for liis researches on the emission of electricity from hot 
bodies, which are the foundation of the science of thermi- 
onics. In the same year W. Rosenhain (now deceased), 
who became Superintendent of the Department in Metal- 
lurgy in the National Physical Laboratory, was elected. 
In 1914 S. W. J. Smith (now Professor of Physics in the 
University of Birmingham) ; in 1915 J. C. McLennan 
(now deceased), late Professor of Physics in the University 
of Toronto ; in 1917 J. W. Nicholson (formerly Professor 
of Mathematics in the University of London) ; in 1918 
E. Gold, Assistant Director of the Meteorological Office ; 
m 1919 G. 1 . Taylor, Yarrow Professor of the Royal 
Society ; in 1921 A. A. Robb, the author of Time and 
Space, and F. W. Aston, who has received a Hughes 
Medal and also a Nobel Prize ; in 1922 G. A. Schott (some- 
time Professor of AppHed Mathematics in the University 



of Wales) ; in 1923 F. Horton (now Professor of Physics 
in Holloway College) ; in 1925 R. Whiddington (now 
Cavendish Professor in the University of Leeds) ; in 1926 
L. F. Richardson, Principal of the Technical College, 
Paisley ; in 1927 E. V. Appleton, lately Professor of 
Physics, King’s College, London, now Jacksonian Pro- 
fessor, Cambridge University, and recipient of a Royal 
Medal ; and in 1930 my son, G. P. Thomson, Professor 
of Physics in the Imperial College of Science and Tech- 
nology, were elected Fellows of the Society. 

(ii) List of Universities and learned Societies in which 
my pupils have held Professorships 

{N.B . — When more than one Cavendish student has held the Profes- 
sorship, the number is enclosed in brackets.) 


Cambridge (4), Oxford, London University — University 
College, King’s College (5), Imperial College of Science 
(4), Royal Holloway College (4), University of Man- 
chester (2), University of Liverpool, University of 
Birmingham, University of Leeds, University of Reading, 
University of Durham, Armstrong College, Newcastle, 
Royal Society, Yarrow Professors (2), Royal Institu- 
tion (2). 


Universities of Edinburgh, Glasgow (2), Aberdeen, St. 


University of Bangor, Aberystwyth (2). 




Trinity College, Dublin, National University of Ireland 
(2), University of Galway. 


University of Montreal (3), University of Toronto, 
Queens University, Kingston, University of Saskat- 
chewan, Hamilton University of Ontario. 



South Africa 

University of Johannesburg, Gray University, Bloem- 


University of Calcutta, Lucknow. 


Harvard, Princeton (5), Yale (2), Columbia, Minnesota, 
Texas, Cincinnati (2), Nebraska, Ilhnois. 


Institut de Physique et de Chimie. 










Cracow, Lemberg. 



Adams, Professor,}. C., 47, 63, 94, 
102, 378 

Agassiz, Alexander, 263 
Aiyat, P. V. Seshu, 313 
Albe, d’, Fournier, 382 
Allcock, W. B., 41 
Arnes,]. S., 246, 259 
Ampere, 239, 333 
Anderson, C. D., 419 
Appleton, E. V., 437 
Armstrong, H. E., 196 
Arnold, E. V., 55-56 
Arrhenius, S., 387, 389, 391 
Ashford, Sir C. E., 114, 123 
Ashton, Thomas, 23 
Asquith, H. H., 220, 237 
Aston, F. W., 357, 436 
Aubert, 107 
Avogadro, 345 
Aymar, 161 

Bacon, Francis, 249 
Baker, H. B., 207 
Baldwin, Stanley, 309 
Balfour, A. ]., 176, 206, 217, 237 
Ball, W. W. Rouse, 305-308 
Bamberger, Louis, 181 
Banks, Sir Joseph, 107 
Barker, Thomas, 12-14, 30, 31 
Barkla, C. G., 345, 404, 406, 407, 
43 ^ 

Barrett, Sir W. F., 162, 298 
Baidett, A. T., 116 
Becquerel, 41 1 , 413 
Bedby, Sir George, 206, 223 
Bed, G. K. A., Bishop of Chichester, 


Benson, Archbishop, 298 
Bentley, A. T., 14-15 
Bentley, R., 318 

Bernard, Miss, 85, 86 
Bethmann HoUweg, 203 
Bevan, A. A., 324 
Bird, Miss Margaret, 302 
Blackett, P. M. S., 419 
Blaikie, L., 142 
Blavatsky, Madame, 153 
Bligh, Ivo, 70 
Blondlot, 395 
Bohr, Niels, 425 
Boze, 251 
Brace, D. B., 428 
Bragg, Sir William, 207, 209, 408 
Bragg, Professor W. L., 408 
Bridge, Captain, 213 
Broglie, Due de, 213 
Broglie, Louis de, 347, 349 
Brookfield, W. H., 269 
Brookfield, Mrs, 269 
Browne, G. F., 299 
Browning, Oscar, 153, 288 
Browning, Robert, 380 
Bryan, W. ]., 170 
Bryan, Captain, 209 
Bryan, G. B., 142 
Bryce, Lord, 13, 294, 299 
Budgett, H. M., 163 
Bumstead, H. A., 142, 143, 187, 
196, 213 
Bunsen, 27 
Bunyan, 230 
Burke, Edmund, 256 
Burke,]. B. B., 142 
Bumand, 65 
Buder, E. M., 279 
Buder, Guy, 279 
Buder, Dr. H. M., 273-280, 300 
Buxton, Foweli, 277 

Callendar, H. L., 114, 13I-I34, 435 



CampbcU, Lewis, 102 
Camden, Marquis of, 237 
Capstick, J. W., 122 
Carlhelm-GyUenskold, Professor, 


Carnot, 9 

Carpenter, Professor, 207, 382 
Cavendish, Lord Charles, 105 
Cavendish, Henry, 104-T09, 255 
Cayley, Professor, 45-47» 102, 286 
Chamberlain, Sir Austen, 79 
Chrec, C., 435 
Chrystal, G., 104 
Churchill, Winston, 219, 220 
Clark,]. W., 65, 322 
Clark, W. G., 282 
Clausius, 10 

Cleveland, President and Mrs, 179 

Clifton, Professor R. B., 99 

Clough, Miss, 85, 86 

Cobb, G. F., 319 

Coffin, C. A., 245 

Collinson, 251 

Colvin, Sidney, 286 

Compton, A. H., 345 

Connaught, Prince Arthur of, 238 

Conrad, R., 360 

Conway, Sir Martin (Lord), 42 

Coolidge, Dr., 247 

Courvoisier, 273 

Cox, Homersham, 41 

Craig-Henderson, W., 141, 143 

Crease, Captain, 307 

Crookes, Sir William, 197, 207, 

237 » 298, 372-383 
Crown Prince (of Germany), 205 
Cunningham, William, 300 
Curie, M. and Mme, 126, 411-413, 

Dalrymple, Charles, 277 
Dalton, John, 7, 8, 28, 29 
Dampier, Sir William. See 
Whetham, W. C. Dampier 
Darwin, Charles, 384 
Darwin, Sir George, 113, 321-322 
Darwin, Sir Horace, 113, 387 

Davidson, Archbishop Randall, 431 
Davisson, C., 346 
de la Rue, Warren, 51, 384 
De Morgan, 39 

Devonshire, 7th Duke of, 100, 237 
Dewar, Sir James, 354, 375, 376, 

401, 424 

Dew-Smith, A. G., 116, 285-287 
Dicey, Professor, 299 
Dixon, Professor H, B., 197 
Duddcll, W., 207 
Duffren, Rev. Howard, 178 
Duim, Sir William, 127 
Dushman, S., 247 

Edward VII, H.M. King, 221 

Edwards, G. M., 55 

Eglin, W., 244 

Eglinton, 147, 148 

Einstein, Professor, 42S-432 

Eliot, George, 282 

Eliot, President, 178, 184, 264, 266 

Elstcr, Dr, 408, 409 

Englcficld, Sir Henry, 107 

ErUcson, Professor, 142 

Erskinc Murray, J., 142 

Evans, Sir John, 194 

Everett, 402 

Ewing, Sir Alfred, 32-1 

Falconer, Hon. 1. K., 65 
Faraday, 94, 221, 391, 392 
Farmer, Dr., 64 
Fine, Professor (and Mrs), 170 
Fisher, Lord, 206, 209, 215, 218- 
221, 237 

Fitzgerald, Edward, 268 
Fitzgerald, Professor G. F., 17, 341, 
408, 424, 427, 429 
Fitzpatrick, Rev. T. C., 114, 121, 
122, 354 
Fizeau, 393 

Fleming, Sir Ambrose, 96, 104, 321 
Fletcher, Sir Walter Morley, 323-324 
Forbes, David, 18 

Foster, Michael, 27, 281-282, 285, 



Franck, 331 

Frankland, Sir Edward, 23 
Frankland, Professor P. F., 207 
Franklin, Benjamin, 106, 249-258 
Fuld, Mrs, 1 81 

Gaede, 374 
Galton, Francis, 155 
Garnett, William, 95, 103, no 
Gauss, 314 
Gay-Lussac, 388 
Geikie, Sir Archibald, 107, 322 
Geitel, Dr., 408, 409 
George V, H.M. King, 217 
George III, 254 
Germer, 346 
Gibbs, Willard, 184-186 
Gibbs, Wolcott, 185 
Gildersleeve, G. L., 169 
Gilman, President, 168, 180 
Gissing, George, 32, 33 
Gladstone, William, 274 
Glaisher, J. W. L., 42, 44-47 
Glazebrook, Sir Richard, 96, 98, 
104, no, 1 13, 120, 121, 122, 128 
Gold, E., 436 

Goldstein, E., 196, 333» 350, 37^, 


Gordon, George, 114, 116 
Gore, Canon, 300 
Gorst, Eldon, 79 
Grant, Miss, 270 
Gray, Rev. H. B., 196 
Gray, Rev. J., 193 
Greenwood, J. G., il 
Grotthus, 326, 327 

Hacker, A., 145 
Haldane, Lord, 43 1 
Hallam, Artliur, 268 
Halsbury, Earl of, 237 
Hamilton, George, 277 
Hamilton, Sir W. R., I4 j 7<5 
Hardy, G. H., 311, 312, 313 
Hare, Archdeacon, ii 
Harlmess, 187 

Harvard, Rev. Edward, 261 
Hayles, W. H., 117, 402 
Heaviside, Oliver, 368 
Helmholtz, von, 29-30, 40, 92, 100, 
196, 203, 226, 280, 376, 391 
Helmholtz, Miss von, 29-30 
Henry, sen. and jun., 7 
Henry, J., 142 
Herdman, Professor, 197 
Herkomer, H. von, 41, 237, 238, 

Hertz, H., 333, 391, 395-397 
Heywood, 28 
Hicks, R. D., 320 
Hicks, W. M., 102 
Hittorf, 384 
Hobson, Professor, 196 
Hodgson, R., 149, 150 
Hoff, van’t, 387, 388 
Hofmann, 378 
Home, D. D., 379-382 
Hopkins, 40 
Hopkins, Sir F. G., 282 
Hopkinson, Bertram, 207 
Hopkinson, John, 2, 44, 385 
Horton, Dr. F., 145, 437 
Housman, A. E., 229, 280, 292, 

Hufif, Professor, 142 
Huggins, Sir W., 382 
HuH, Professor, 143 
Humphry, Mrs, 48 
Huxley, T. H., 24, 27, 99, 421 

Image,). M., 34, 35 
Irving, II 

Jackson, Henry, 84, 242, 269, 289- 

293, 309 

Jebb, Sir Richard, 292, 300 
Jenkinson, F. J. H., 320 
Jevons, Stanley, 13 
Johnson, Dr., 226, 291 
Johnson, G. W., 55 
Johnstone, Sir Duncan, 196 
Joule, James Prescott, 7, 8-10, 134, 



Kaiser, the, 205 
Kaufmann, 339, 340 
Kaye, Dr. G. W. C., 375 
Kelviit, Lady, 424 

Kelvin, Lord ('cee also William 
Thomson), 50, 51, 134, 194, 240, 
322, 386, 394, 397, 408, 420-425 
Kemp, Mrs, 34 
Kinpley, Charles, 272 
Kipling, Riidyard, 238, 319 
KirchhofF, 18, 47, 280 
Kohlrausch, 393 

Laborde, 412 
Lagrange, 76 

Lamb, Sir Horace, 17, lor, 196, 


Langevin, P., 142, 145, 2ti 
Langley, J. N., 323 
Langmuir, 1 ., 247, 374 
Lapsley, G. T., 262 
Larmor, Sir Joseph, 41, 48, 49, 63, 
195, 344, 37« 

Lauc, von, 34<5, 407 
Laurence, R. V., 230 
Lauricr, Sir Wilfred, 195 
Lavoisier, 257 
Leathern,]. G., 142 
Lebedew, 373 
Lempfert, R. G. K., 142 
Lenard, Professor, 408 
Lenox-Conyngham, Sir Gerald, 282 
Lewes, G. H., 282 
Lincoln, F., 116-11 j 
Litdewood, J. E., 314 
Livcing, G. D., 238 
Lockycr, Norman, 27, 99 
Lodge, Sir Oliver, 148, 152, 154, 
207, 254, 379, 396-397, 408, 424 
Lorentz, H. A., 368, 427, 429 
Lome, Marquis of, 25 
Lubbock, Sir John, 24, 27 
Lucas, A. P., 70 
Lucas, Keith, 231 
Lusliington, 268 
Lyman, Mrs, 264 
Lyman, T., 142, 196, 263 

Lyttelton, Hon. Alfred, 70 
Lyttelton, Hon. Arthur, 300 
Lyttelton, Hon. E., 70 

MacAlistcr, Sir Donald, 104 
MacDonald, George, ii 
MacDonald, Professor, 196 
Mackenzie, Professor, 142 
MacMahon, Professor, 196 
Mahaffy, Professor, 204 
Maitland, F. M., 297, 299, 300 
Manners, 65 
Mansel, 306 

Marconi, Mnrehese, 409 
Marshall, Alfred, 238 
Maskelyn, 107 

Maurice, Frederick Denison, ii 
Maxwell, Clerk, 39, 40, 43, 57, 92, 
96, 97, 100-105, 109, III, 134, 
185, 239, 240, 281, 344, 364, 365, 
3d7. 373, 391-394, 39f>. 405, 

426, 42X, 431 

McClelland,]. A., 137, 142, 436 
McConnel, 'L. C., 118-119 
McEvoy, A., 302 
McKenna, R., 220 
McKinley, 170 

McLennan,]. C., 142, 201, 223, 

43 f> 

McTaggart, ]. McT. E., 229, 302-305 

Mercer, General Hugh, 179 

Mesmer, 256 

Michclson, A. A., 426 

Moissaii, Henri, 223, 224 

Moltcno, ?. A., 128 

Monckton-Milncs, 269 

More, L. T., 143 

Morlcy, 426 

Morton, E. ]. C., 42 

Moseley, H. G. ]., 407 

Mott, C. F., 142 

Moulton, Lord, 384-387 

MiiUer, H., 384 

Mullins, John, 162 

Munro, H. A. ]., 69-70 

Miinsterberg, H., 197 

Murray, Profes.sor Gilbert, 156-158 



Myers, F. W. H., 147, 148, 149, 151 
Myers, J. L., 196 

Nabb, L, 142 

Natanson, W., 131 

Neville, E. H., 311 

Newall, H. F., 104, 120, 121, 142 

Newton, Isaac, 8, 41, 49, 50, 99, 


Nichols, Professor, 143 
Nicholson, J. W., 436 
Niven, Charles, 43 
Niven, James, 43 
Niven, W. D., 42-44, 236 
Noble, Sir Andrew, 238 
Nock, A. D., 262 
Northumberland, Duke of, 237 
Novak, V., 142 

Occhialini, G. P. S., 419 
Olearski, K., 13 1 
Onnes, Kamerlingh, 134 
Ostwald, Professor, 390 
Owens, R. B., 142, 243 

Paget, Sir George, 72, 109 
Paget, Sir Richard, 207, 213 
Palladino, Eusapia, 148-152 
Paramellc, Abbe, 160 
Parry, R. St. J., 292, 308-310 
Parsons, Sir Charles, 206, 223, 224, 


Patterson, J., 142 
Patton, Dr., 178 
Peace,}. B., 135, 142 
Peirse, Sir Richard, 206 
Pfeffer, 387, 388 
Planck, M., 347, 349, 410 
Playfair, Professor, 108 
Pliicker, 376 
Pope, Sir William, 207 
Postgate, J. P., 320-321 
Porson, R., 306 

Poynting, J. H., 22-33, 95, 196, 
198, 341 

Prain, Sir David, 196 
Preece, Sir William, 409 

Priestley, 251 
Pringle, Sir John, 254 
Prior, Joseph, 34, 35, 287-289 
Przibram, K., 143 
Pye, W. G., 1 1 6, 286 

Rackham, 46 

Ramanujan, Srinivasa, 310-314 
Ramsay, Sir James, 237 
Ramsay, Sir William, 400, 401 
Rankine, 15 
Raoult, 389 
Rashdall,Dr., 62 

Rayleigh, Lord (the late), 41, 96, 97, 
98, 105, 109-114, 134, 149, 150, 
155, 158, 194, 336-341, 374, 380, 

Rayleigh, Lord, 283 ; see also Strutt 
Reid, H. F., 131 
Remsen, Ira, 169 

Reynolds, Osborne, 12, 15-18, 373 
Richardson, L. F., 437 
Richardson, O. W., 142, 283, 436 
Richer, Professor, 148, 149, 150, 152 
Ridley, Sir M., 277 
Robb, A. A., 140, 142, 436 
Roberts, H. A., 74 
Rogers, Will, 244 
Rontgen, W. K., 126, 325, 401-403 
Roscoe, H. E., 12, 33-30, 99 
Roscoe, Mrs, 29 
Rosenhain, W., 436 
Routh, Sir Randolph, K.C.B., 39 
Routh, Dr., 35-43 
Routh, Mrs, 41 
Rowland, Henry, 169 
Rucker, A. W., 27 
Rudge, W. A. D., 142 
Rutherford, Lord, 137, 142, 145, 
196, 207, 208, 313, 383, 331, 407» 
409, 411, 413, 414, 421, 435 

Salisbury, Lord, 274 
Sandeman, Archibald, 13 
Sanderson, Lord, 431 
Schmidt, G. C., 41 1 



Schorlcnimcr, C., 29 
Sclmcidcr, Rudi, 152 
Schott, G. A., 436 
Schuster, Sir Arthur, 22, 95, 97, t04, 
III, 145, 339, 373 
Scott, A. J., 1 1 
Scott, Miss, 84 
Scrutton, Lord Justice, 54 
Searle, G. F. C., 114-115, 123, 142, 
43 <5 

Scclcy, Sir John, 272 
Shakespeare, G. A., 142 
Shaw, Sir Napier, 74, 96, 98, no, 
120, 123, 12S, 142 
Shipley, Sir Arthur, 196, 323 
Sidgwick, Henry, 152, 274, 293-300 
Sidgwick, Mrs, tii, 149, 152, 156, 
293, 298, 299 
Sinclair, D. S., 1 16 
Skinner, S., 114, 123, 142 
Smith, Sir F, E., 222 
Smith, H. J. S., 45, 294 
Smith, S. W. J., 142, 436 
Smithells, A., 51 
Smoluchowski, Professor S. T., 


Spedding, 269 
Spottiswoode, W., 384, 385 
Stanford, Lcland, 266 
Starling, Professor, 196 
Steel, D. Q., 70 
Steele, A. G., 70 
Stephen, Leslie, 294, 300, 316 
Stevenson, R. L., 285 
Stewart, Balfour, 12, 18-22, 24 
Stewart, H. F., 320 
Stokes, Sir George, 40, 41, 45, 47, 
48-52, 99, 102, 134, 240, 378, 404, 
408, 421 

Stokes, Lady, 49 
Stoney, Gerald, 207 
Strutt, Hon. R. J., 142, 435 (now 
Lord Rayleigh) 

Stuart, C. E., 231 
Stuart, James, 43, 321 
Sturgeon, 7 

Tait, Professor P. G., 14, 22 
Talbot, J., 142 
Tatham, Geoffrey, 231 
Taylor, G. L, 436 
Taylor, M. M., 34, 35, 319-320 
Taylor, Sedley, 319 
Tennyson, Alfred, 268 
Thackeray, W. M., 268, 269, 271, 

Thomas, Miss Carey, 260-261 
Thompson, C. M., 55 
T’hompson, W. H., 34, 267-273, 

Thompson, Mrs, 270 
Thomson, G. P., 347-349, 437 
Thomson, William (.see also Lord 
Kelvin), 9, 40, 45, 68, 94, 100 
Thorncly, T., 288 
Thrclfall, R., 71, 117-120, 145, 222, 
224, 435 

Townsend, J. S. E., 129, 137, 142, 
332, 342, 435 

Trevelyan, Sir G. O., 237, 277 
Trotter, CoutK, 34, 35, 153, 274, 

Tuttoii, Professor, 197 
Tyndall, j., 24 

Van Dyke, Henry, 178 
Varlcy, Cromwell, 423 
Vegard, Profc.ssor, 143 
Venn, ]. A., 307 
Vcrrall, A. W., 70, 320 
Verrall, Mrs, 149 
Victoria, Queen, 422 
Vincent, J. H., 142 

Wade, E. B. H., 142 
Walker, Sir G. T., 311 
Walker, G. W., 142 
Wallace, A. R,, 298 
Waran, 374 

Warburg, Professor (and Mrs), 

Ward, Sir Adolphus, 13, 23, 32 
Ward, James, 299, 300-302 
Ward (of Magdalene), 69 



Wasliingtoii, Booker, i68 
Watson, 352 
Watt, J. C„ 68 
Weber, 393 
Wells, H. G., 303 
West, Dean, 1 71, 174 
West, H. H., 54 
Westcott, Dr. B. F., 276 
Whetham, W. C. Dampier, 114, 
123, 130, 135. 142. 435 
Whewell, WiUiam, 267-268, 274 
Whiddington, R., 437 
White, Sir William, 195, 196 
Whitehead, A. N., 262 
Whitehouse, O. E., 422 
Whitfield, W. H., 55 
Whitney, Dr., 375 
Wiechert, E., 339 
Wilamowitz-MoUendorfF, Pro- 
fessor, 204 

Wilberforce, L. R., 121, 122, 129 

Williamson, W. C., 12 
Willows, R. S., 27 
Wills, R. L., 142 
Wilson, Benjamin, 253 
Wilson C. T. R., 124, 126, 135, 
142, 329, 332, 341, 416-420, 435 
Wilson, H, A., 142, 343, 436 
Wilson, Woodrow, 170-176, 179, 

Wollaston, Dr., 108 
Wood, A., 145 
Wood, Derwent, 145 
Wood, Professor R. W., 246 
Woodward, Smith, 196 
Wright, Aldis, 69, 84 
Wright, C. S., 222 
Wright, R. T., 47 

Zanzigs, 155, 156 
Zeeman, P., 358 
Zeleny,}., 142, 187, 331 



Adams Prize, 94 
Age of the earth, 420, 421 
America : visited in i8g6, 164-181 ; 
in 1 ^ 0 % 181-193 ; 243- 


American football, 179, 189-192 
American Philosophical Society, 

American Universities : progress in, 
187-189 ; Womens’, 87. See also 
Bryn-Mawr, Harvard, Johns Hop- 
kins, Leland Stanford, Princeton, 

Analysis ; chemical by positive 
rayS', 355 seq. 

“ Aposdes ”, the, 274, 293, 302 
“ Application of Dynamics to 
Physics and Chemistry,” 77 
Argon, 27 ; discovery of, 239, 397 
et seq. 

Astrology, 318 
Astronomical Club, 46 
Atlantic Cable, 422 
Atomic Theory, 8, 28, 50-51 
Atoms, doubly charged, 359 ; 
negatively charged, l 6 i 

Bala Lake, 212 
Baltimore, 165-170, 246 
Banff, 199 
Baseball, 165-166 
Bell Telephone Company, 248 
Berlin University Commemoration, 

Billiards and mathematics, 80 
Bimetallism, 170 
“ Blunderbuss, The ”, 229 
Board of Invention and Research, 
143, 206 et seq. 

' Boston, 184, 249 

British Association, 322, 424 ; meet- 
ing at Oxford, i 8 g 4 , 400 ; at 
Liverpool, i 8 g 6 , 408 ; at Bristol, 
383 ; at Dover, i 8 gg, 341 ; 
at Winnipeg, igog, 194-199 
Bryn-Mawr University, 84, 87, 261 

Cambridge : in the seventies— the 
Long Vacation, 52-53 ; the 
Scholar’s Table, 54-56 ; com- 
pared with present day, 64-74 
(theatricals, 64-66 ; games, 66- 
70 ; “ Blues ”, 70-71 ; fashions, 
71-72 ; careers, 73-74) ; advent 
of women, 64, 72 ; i8'jg-84, 75- 
98 ; compulsory Greek, 35, 233, 
292, 304 ; status of women 
students, 83-90, 292, 304 ; Col- 
lege Fellowships, 90 ; increase in 
University residents, 91 ; during 
the War, 228-242, 303 ; relation 
between University and Colleges, 
295-297 ; Engineering School, 
321 ; Physiological School, 323 ; 
see also Trinity College 
“ Cambridge Review ”, 87 
Cambridge Scientific Instrument 
Company, 287 
Canada, visit to, 194-202 
Carnot’s cycle, 9 
Cathode rays, 91, 248, 333, 376 
Cavendish College, 78 
Cavendish Laboratory, 95-98 ; His- 
tory, 99-114; staff, 1 14-124; 
classes for Medical Students, 121- 
123 ; increase in number of 
Science Students, 123-124, I3<^ 
137 ; finance, 124-128 ; admis- 
sion of Research Students, 128, 
136-142; work i 8 $ 4 -gSf 128- 



136 ; i8g6-igoo, 136-146, 281 ; 
Appendix, 435-438. 

Caven<lisk Physical Society, 130, 


Cheetham, 1-2 

Chemical analysis by positive rays, 

355 ef seq. 

Chemical Combination, law of, 8, 


Classical Tripos, alteration in, 291 
Colour question in America, 168 
“ Conditional Immortality ”, 51-52 
Contraction of moving bodies, 367, 


Conscientious objectors, 234 
Conservation of Energy, 7-9, 21 
Corpuscles. See Electrons 
Cosmic Rays, 332 
Coutts Trotter Studentship, 283 
Crookes, Sir William ; radiometer, 
372 et seq . ; cathode rays, 376 
et seq. ; psychic force, 379 J 
spiritualism, 379 et seq. 

“ Crossing the Bar ”, 317 

Dalton Chemical Scholarship, 29 
Debutantes in Baltimore, 168 
De la Rue and Muller striated elec- 
tric discharge, 3 84 
Descartes on Space, 432 
Dewer method of producing high 
vacua, 354, 375 

Diamonds from carbon, 223-224 
Diffusion of ions, 332 
Diktancy, 17 
Divining rod, 159-162 
Ducks, canvas-back and redhead, 


Dynamics : Newtonian mechanics, 


Ectoplasm, 152 

Education, Committee on, 224-227 
Einstein Theory of Relativity, 426 
Electric sparks, 135 
Electric waves, 27 

Electrical measurement, 111-113, 


“ Electrical Researches of the Hon- 
ourable Henry Cavendish ”, 105 
Electrical resistance and tempera- 
ture, I 3 2-1 3 4 

Electricity : moving charges of, 91- 
94 ; passage of, through gases, 
117-118, 135-136, 164 ^ 

“ Electricity and Matter ”, 181 
Electrolytic Dissociation, 387 et seq. 
Electromagnetic field, 10 1 
Electrometer method of investigat- 
ing positive rays, 362, 363 
Electron, 253-258, 332 et seq. ; 
mass of, 339 ; electric charge on, 
341 ; number of electrons in the 
atom, 343 ; diffraction of, 346 ; 
scattering of, 345 

“ Electron m Chemistry, The ”, 258 
Electronic Waves, 346 et seq. 
Emanations, radio-active, 412 
Energy : “ transformation ” or 

“transference” of?, 21, 75-76; 
transmission in electromagnetic 
field, 22, 92 ; see also Conserva- 
tion of Energy 
English, teaching of, 3 
Ether, 369 ; and space, 432 

Falkland Islands, battle, 218 
Famborough, 26 
Franck, mobiHty of ions, 331 
Franco-German War, 5 
Franklin Institute, 244, 246, 258-259 

Galton’s whistle, 155 
Games : in the sixties, 5 ; in the 
seventies, 66-70 

Gaseous ions : diffusion of, 332 ; 
mobility of, 331 ; recombination 

of, 331 

General Electric Company, 26, 245, 
Girton, 85, 89 
Goldstein cadiode rays, 333 
Grocers’ Company, 32 



Grotthus’ chains, 327 
Group velocity, 349 

H3^ 3<S3 ^ . 

HamUtonian Equations, 76 
Harvard University, 184 : links 
with Trinity College, 262 ; pro- 
gress, 187 ; revisited, 247 ; 261- 

Harwich, 210 
Hawkeraig, 209-2 lO 
Heat, Joule’s researches on, 8-9 
Heaviside : Moving electrons, 367 ; 
Ellipsoid, 368 

Hertz : discovery of electric waves, 
391 ei seq. ; on Cathode rays, 333 
High vacua, 354, 375 scq. 

“ History of the Cavendish Labora- 
tory ”, 121, I43-U4 
“ History of Trinity College , 307 
Homerton College, 79 
Hypnotism, 257 

Imperial Chemical Industries, 26 
Inaudible sound, 155 
Induction coils, researches on, 97 
Industry, see Research and Industry 
Ions in gases, see Gaseous ions 
Isotopes, 357 

Jolms Hopkins University, 168-169, 
246, 259 

Jutland, battle of, 219 

Kanalstrahlen, sec Positive rays 

Laboratory : at Owens College, 
19 ; Sir Henry Roscoe’s, 39 ; 
Clarendon, 99 ; at University of 
Sydney, 119-120; at Toronto, 
201 ; in Schools, 227 ; of Bell 
Telephone Company, 348 
Lagrangian Equations, 76 
Lake Louise, 200 

Latin : teacliing of, 3 ; new pro- 
nunciation, 321 
JLaw Tripos, 58 

Leak, “ residual ”, 332 
Lecturing, importance of freshness 
in, 16, 43-44, 48, 82, 201, 265 
Lelaiid Stanford University, 266 
Leyden jar, 106, 135, 250-253, 257, 

Light, Electromagnetic Theory of, 

Lightning conductors, 106, 353-254 
Lodge, experiments on electric 
waves and on resonance, 397 

Manchester, i, 7-8, lo-ii, 23-24, 


Manchester Literary and Philo- 
sophic Society, 7-8, 38 
Mass : due to electric charge, 365 ; 
alteration with velocity, 368 ; 
spectrograph-, 357 
“ Mathematical Recreations ”, 306 
Madiematical Tripos, 35-38, 5<5-63, 
84, 96, 99, 129, 233 
Mathematics, teaching of, 4, 13-15, 
31, 35-39 

Maxwell’s Theory, 393 et seq. 
Medical Research Council, 324 
Membranes, semi-permeable, 387 
Mercury, multiply charged atoms, 

Mobihty of ions : Rutherford on, 
331 ; Zeleny, 331; Franck, 331 

“ N ” rays, 395 

National Physical Laboratory, 35- 
26, 203, 240 

Natural Sciences Tripos altered, 

“ Nature ”, 22, 159, 294 
Negatively charged atoms, 3^1 
Neon, isotope or, 356 
New Haven, 181 seq. 

“ New MachiavelH, The , 3^3 
New View of the Origin of 
Dalton’s Atomic Theory ”, 8 
New York, 243-246 
Newnham, 85-86, 89 
Newtonian dynamics, 93, 37© 



Olim re-determined, 111-113 
Osmotic Pressure, 387 
Owens College, the : 2-3 » 10-33 *> 
foundation, 10 ; development, 
11-12, 23 ; engineering course, 
12, 15 ef seq., 30 ; teaching staff, 
13-30; some pupils, 32-33 

Pacific, trip to, 199 
“ Pelicotetics ”, 13 
Penny Lectures, 24 
“ Pentacle Club ”, 306 
Philadelphia, 249, 251, 253, 258- 

Phoneidoscope, 319 
Phosphorus, use in the war, 222 
Photon, nature of, 410 
Planck’s constant, 347. 349 
Planck’s Law, 410 
Platinum wire as thermometer, 132 
“ Poor Richard’s Almanac ”, 250 
Positive ray, 350 seq. 

Positive ray, electrometer method, 

Poynting vector, 22 
Princeton : description, 171 ; social 
clubs, 171 ; President Wilson 
controversy, 1 72-175 ; Sesqui- 
centenary, 170, 178-180 ; de- 
velopment, 1 81, 187 ; revisited, 


“ Psychic force , 379 
Psychical research, 147-163, 298 
Pumps, air, 374 et seq. 

Quantum Theory, Bohr, 425 
Quantum, structure of, 410 
Quaternions, 14 
Quebec, 194 

Radio-activity, 41 1 seq. ; of 
wells, 1 60-1 6 1 
Radiometer, 17, 372 
Radium, 27, 126 ; discovery of, 412 
Rays : cathode, 333, ^76; cosmic, 
332 ; “ N ”, 395 ; positive, 350 ; 
X (R6ntgen)v 27, 250, 325 
Recombination of ions, 331 

Reichanstalt, the, 203 
Relativity, 426-433 
Research : methods of Osborne 
Reynolds, 15 ; of Balfour 
Stewart, 19-21 ; of Henry 
Cavendish', 105 ; and Industry, 
25-27, 29 ; educational value, 283 
Research scholarships, 29, 61-62 
Research students in Cavendish 
Laboratory, 136 ci seq. 

Reynolds’ constant, 16 
Rontgen rays, 27, 250, 325 
Royal Institution, Friday evening 
discourses, 16 

Royal Society: 51, 227, 312, 322; 
Proceedings, 21 ; Philosophical 
Transactions, 45» 77» HS ; Caven- 
dish and, 107-109 ; Fellowship 
of, 144 ; Appendix, p. 43 5 ; Copley 
medal, 185 ; and Franklin, 252- 
253, 256 

Science, improvement in teacliing, 
24-27, 99, 224 

“ Scientific Papers of Lord Ray- 
leigh ”, 239 

Scholarships, 31-32, I73, 225 ; see 
also Research scholarships 
School-leaving age, 225-226 
Sea lions, 21 1-2 12 
Sea-sickness cure, 180 
Shorthand, Callcndar’s, 134 
“ Short History of Mathematics ”, 

Silliman Foundation, 181 
Sky-scrapers, 243-244 
Slate-writing, 147-148 
Soaring of birds, 113 
Society for Psychical Research : 
Proceedings, 156 ; foundation, 

Solution, 387 
Space and ether, 432 
Spectrograph-mass, 357 
Spin of baU, 166 
Spiritualism, 379 
Striations, 384 



Submarine-detection : by ear, 207- 
208 ; by microphone, 209 ; by 
physical apparatus, 210-211 ; by 
sea lions, 21 1— 212 

Sun-spots, 20 

Telepathy, 154-158 

Thomson, Sir J. J. : boyhood, 1-7 ; 
early education, 2—5 \ at The 
Owens College, 2, ii-33 ; first 
researches, 20-21 ; accident in 
laboratory, 20 ; gives up engin- 
eering, 30 ; undergraduate at 
Cambridge, 34-74 *> Second 
Wrangler, 63 ; Fellowship at 
Trinity, 75-79 ; first private 
pupds, 79 ; Assistant Lecture- 
ship, 80-82 ; researches, 1880-84^ 
91-95, 97-98 ; Lectureship, 97- 
98 ; elected Cavendish Professor, 
98 ; researches i88$-g5f 117- 

118, 120, I35-I3d ; and Caven- 
dish Laboratory, Ii4-I4<5 ; ^d 
psychical research, 147-15 5 ; visits 
to America in i8g6, 164-181 ; m 
igo3, 181-193 ; to Canada in 
jpop, 194-202 ; to Berlin in ipio, 
202-205 ; activities during war, 
206-242 ; President of Royal 
Society, 227-228 ; Master of 
Trinity, 227, 241-242 ; visit to 
America in ip25, 243-266 
Three-wire system, 385 
“ Treatise on the Motion of Vortex 
Rings ”, 95 

Trinity College : author as under- 
graduate at, 34-74 ; lecturers and 
coaches at, 35-52 ; scholars at, 
54-56 ; Fellowship at, 77-79 5 
the “ Bachclor^s Table ”, 78 ; 
author admitted to Mastership 
of, 241-242 ; some Trinity men. 


267-325 ; method of election 
to Mastership, 273 ; election 
to Fellowships, 282-283 ; tenure 
of Fellowships, 284-285 ; Wine 
Committee, 289, 315 ; abolition 
of religious tests for Fellowships, 
292, 294 ; Garden Committee, 

Uncreasable cotton, 27 

Union Library of Philadelphia, 258 

“ Unseen Universe ”, The, 22 

Vortex rings, 17, 94, 120 

War ; -work, 206-224 ; inventions, 
21 3-217 ; Cambridge during, 
228-234, 303 

Water : flow through cylindrical 
tubes, 16 ; movement of sphere 
through, 93 

Water-dowsing, 158-163 
West Point Military Academy, 176- 

Whist, 55 
Wilson Tracks, 416 
Winnipeg, 194-195 
Wireless telegraphy, 137, 409 
“ Wooden Spoon ”, the, 81 
Women’s education, 297 ; see also 
Cambridge, status of women 

X-Rays, 325 et seq. ; tubes for pro- 
ducing, 248 

Yale University, 181 et seq. ; 
smdents’ clubs, 183-184 ; pro- 
gress, 187 ; re-visited, 247 

Zeppelins, 204, 214, 228, 303 
Ziegfeld Follies, 244